Organic electroluminescence device

ABSTRACT

The present invention relates to an electroluminescence device having high luminous efficiency (for example, external quantum efficiency) and high durability and causing little chromaticity shift after device deterioration. The present invention also relates to an organic electroluminescence device material comprising a substrate having thereon a pair of electrodes and at least one organic layer between the electrodes, the organic layer containing a light emitting layer, wherein the light emitting layer contains a metal complex having a group represented by formula (I).

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 13/393,272, filed Feb. 29, 2012, now U.S. Pat. No. 8,945,725,issued Feb. 3, 2015, which is a 35 U.S.C. § 371 national phaseapplication from, and claiming priority to, International ApplicationNo. PCT/JP2010/064664, filed Aug. 24, 2010, which claims priority toJapanese Patent Application No. 2009-201150, filed Aug. 31, 2009, all ofwhich applications are incorporated by reference herein in theirentireties.

TECHNICAL FIELD

The present invention relates to a luminescence device capable ofconverting an electric energy into light and thereby producingluminescence. More specifically, the present invention relates to anorganic electroluminescence device (luminescence device or EL device).

BACKGROUND ART

An organic electroluminescence (EL) device is attracting as a promisingdisplay device because high-luminance intensity luminescence can beobtained with a low voltage. An important characteristic value of thisorganic electroluminescence device is a power consumption. The powerconsumption is represented by a product of a voltage and a current, andas the voltage value necessary for obtaining desired brightness is lowerand the current value is smaller, the power consumption of the devicecan be more reduced.

In the production of an organic electroluminescence device, as for themethod to form a thin film that is an organic layer provided between apair of electrodes, a vapor deposition process such as vacuum depositionand a wet process such as spin coating method, printing method and aninkjet method are being performed.

Among these, when a wet process is used, an organic compound polymerwhose deposition is difficult by a dry process such as vapor depositioncan be used, and in the case of use for a flexible display or the like,the wet process is suitable in view of durability such as flexibilityand film strength and is preferred particularly when fabricating alarge-area device.

However, an organic electroluminescence device obtained by the wetprocess has a problem that the luminous efficiency or device durabilityis poor.

In recent years, the device efficiency is progressively increased byusing a phosphorescent material. As for the phosphorescent material, aniridium complex, a platinum complex and the like are known (see, forexample, JP-A-2001-247859 and JP-A-2007-19462), but a device satisfyingboth high efficiency and high durability has not yet been developed.

Also, an organic EL device where a specific phosphorescence materialsubstituted with a specific kind of an alkyl group at a specificposition with an attempt to obtain a material capable of realizing highefficiency and low voltage of a device is used as a light emittingmaterial has been reported (see, for example, JP-A-2008-210941 and US2008-0297033). In JP-A-2008-210941, an organic EL device containing acompound having a cyclopropyl group as the substituent is described, butthis is insufficient in view of luminescence quantum efficiency, drivevoltage and durability, and more improvements are being demanded.

Furthermore, conventional devices sometimes cause a chromaticity shiftafter device deterioration, and also in this respect, improvements arebeing demanded.

SUMMARY OF INVENTION

An object of the present invention is to provide an organicelectroluminescence device having high efficiency and high durabilityand causing little chromaticity shift after device deterioration.Another object of the present invention is to provide a phosphorescencematerial having a specific alkyl group, which is suitable for use in thedevice.

These objects have been attained by the following techniques.

[1]

An organic electroluminescence device including a substrate havingthereon a pair of electrodes and at least one organic layer between saidelectrodes, the organic layer containing a light emitting layer,

wherein any one layer of the organic layer contains a metal complexhaving a group represented by the following formula (I).

(In formula (I), R₁ represents an alkyl group, each of R₂ and R₃independently represents a hydrogen atom or an alkyl group, n representsan integer of 0 to 6, and Z represents a saturated 5- to 8-memberedring.)[2]

The organic electroluminescence device according to [1],

wherein in formula (I), n represents an integer of 1 to 3.

[3]

The organic electroluminescence device according to [1] or [2],

wherein in formula (I), n is 1.

[4]

The organic electroluminescence device according to any one of [1] to[3],

wherein in formula (I), each of R₂ and R₃ represents a hydrogen atom.

[5]

The organic electroluminescence device according to any one of [1] to[4],

wherein in formula (I), Z represents a cyclopentyl group or a cyclohexylgroup.

[6]

The organic electroluminescence device according to any one of [1] to[5],

wherein the metal complex having a group represented by formula (I) is ametal complex represented by the following formula (1).

(In formula (1), M¹¹ represents a metal belong to Groups 8 to 11 in theperiodic table of elements, A¹¹ represents a nitrogen atom or a carbonatom, X¹¹ represents an oxygen atom, a sulfur atom, a substituted orunsubstituted nitrogen atom or a single bond, Y¹¹ represents a linkinggroup or a single bond, L¹¹ represents a partial structure having anatom bonded to X¹¹, Z¹¹ represents an aromatic nitrogen-containingheterocyclic ring, each of L¹² and L¹³ represents a carbon atom, anitrogen atom, an oxygen atom or a phosphorus atom, E¹¹ represents anatomic group for forming a bidentate ligand together with L¹² and L¹³, krepresents an integer of 1 to 3, l represents an integer of 0 to 2, k+lis 2 or 3, S¹¹ represents a group represented by formula (I), nrepresents an integer of 1 to 4, and each S¹¹ may be the same as ordifferent from every other S¹¹.)[7]

The organic electroluminescence device according to [6],

wherein the metal complex represented by formula (1) is a metal complexrepresented by the following formula (2).

(In formula (2), M²¹ represents a metal belong to Groups 8 to 11 in theperiodic table of elements, each of A²¹ to A²³ independently representsa nitrogen atom or a carbon atom, Z²¹ represents an aromaticnitrogen-containing heterocyclic ring, Z²² represents an aromaticheterocyclic ring or an aromatic hydrocarbon ring, each of L²² and L²³represents a carbon atom, a nitrogen atom, an oxygen atom or aphosphorus atom, E²¹ represents an atomic group for forming a bidentateligand together with L²² and L²³, k represents an integer of 1 to 3, lrepresents an integer of 0 to 2, k+l is 2 or 3, each of S²¹ and S²²independently represents a group represented by formula (I), each of nand m represents an integer of 0 to 4, n+m is an integer of 1 to 4, andeach S²¹ or S²² may be the same as or different from every other S²¹ orS²².)[8]

The organic electroluminescence device according to [7],

wherein the metal complex represented by formula (2) is represented bythe following formula (4).

(In formula (4), M⁴¹ represents a metal belong to Groups 8 to 11 in theperiodic table of elements, each of R⁴³ to R⁴⁶ independently representsa hydrogen atom or a substituent, each of B⁴¹ to B⁴⁴ independentlyrepresents a nitrogen atom or C—R⁴⁷, R⁴⁷ represents a hydrogen atom or asubstituent, each R⁴⁷ may be the same as or different from every otherR⁴⁷, each of L⁴² and L⁴³ represents a carbon atom, a nitrogen atom, anoxygen atom or a phosphorus atom, E⁴¹ represents an atomic group forforming a bidentate ligand together with L⁴² and L⁴³, k represents aninteger of 1 to 3, l represents an integer of 0 to 2, k+l is 2 or 3,each of S⁴¹ and S⁴² independently represents a group represented byformula (I), each of n and m represents an integer of 0 to 4, n+m is aninteger of 1 to 4, and each S⁴¹ or S⁴² may be the same as or differentfrom every other S⁴¹ or S⁴².)[9]

The organic electroluminescence device according to [8],

wherein the metal complex represented by formula (4) is represented bythe following formula (5).

(In formula (5), M⁵¹ represents a metal belong to Groups 8 to 11 in theperiodic table of elements, each of R⁵³ to R⁵⁹ and R⁵¹⁰ independentlyrepresents a hydrogen atom or a substituent, each of L⁵² and L⁵³represents a carbon atom, a nitrogen atom, an oxygen atom or aphosphorus atom, E⁵¹ represents an atomic group for forming a bidentateligand together with L⁵² and L⁵³, k represents an integer of 1 to 3, lrepresents an integer of 0 to 2, k+l is 2 or 3, each of S⁵¹ and S⁵²independently represents a group represented by formula (I), each of nand m represents an integer of 0 to 4, n+m is an integer of 1 to 4, andeach S⁵¹ or S⁵² may be the same as or different from every other S⁵¹ orS⁵².)[10]

The organic electroluminescence device according to [7],

wherein the metal complex represented by formula (2) is represented bythe following formula (7).

(In formula (7), M⁷¹ represents a metal belong to Groups 8 to 11 in theperiodic table of elements, each of R⁷³ to R⁷⁶ independently representsa hydrogen atom or a substituent, each of A⁷¹ and A⁷² independentlyrepresents a nitrogen atom or a carbon atom, each of D⁷¹ to D⁷³independently represents an atom selected from carbon, nitrogen, oxygen,sulfur and silicon, the bond between atoms in the 5-membered ring formedby D⁷¹ to D⁷³, A⁷¹ and A⁷² represents a single bond or a double bond,each of D⁷¹ to D⁷³ when these can be further substituted may have asubstituent, each of L⁷² and L⁷³ represents a carbon atom, a nitrogenatom, an oxygen atom or a phosphorus atom, E⁷¹ represents an atomicgroup for forming a bidentate ligand together with L⁷² and L⁷³, krepresents an integer of 1 to 3, l represents an integer of 0 to 2, k+lis 2 or 3, each of S⁷¹ and S⁷² independently represents a grouprepresented by formula (I), each of n and m represents an integer of 0to 4, n+m is an integer of 1 to 4, and each S⁷¹ or S⁷² may be the sameas or different from every other S⁷¹ or S⁷².)[11]

The organic electroluminescence device according to [7],

wherein the metal complex represented by formula (2) is represented bythe following formula (9).

(In formula (9), M⁹¹ represents a metal belong to Groups 8 to 11 in theperiodic table of elements, each of R⁹³ and R⁹⁴ independently representsa hydrogen atom or a substituent, R⁹⁵ represents a hydrogen atom or asubstituent, each of B⁹¹ to B⁹⁴ independently represents a nitrogen atomor C—R⁹⁶, R⁹⁶ represents a hydrogen atom or a substituent, each R⁹⁶ maybe the same as or different from every other R⁹⁶, each of L⁹² and L⁹³represents a carbon atom, a nitrogen atom, an oxygen atom or aphosphorus atom, E⁹¹ represents an atomic group for forming a bidentateligand together with L⁹² and L⁹³, k represents an integer of 1 to 3, lrepresents an integer of 0 to 2, k+l is 2 or 3, each of S⁹¹ and S⁹²independently represents a group represented by formula (I), each of nand m represents an integer of 0 to 4, n+m is an integer of 1 to 4, andeach S⁹¹ or S⁹² may be the same as or different from every other S⁹¹ orS⁹².)[12]

The organic electroluminescence device according to [7],

wherein the metal complex represented by formula (2) is represented bythe following formula (12).

(In formula (12), M¹²¹ represents a metal belong to Groups 8 to 11 inthe periodic table of elements, each of R¹²³ to R¹²⁵ independentlyrepresents a hydrogen atom or a substituent, each of B¹²¹ to B¹²⁴independently represents a nitrogen atom or C—R¹²⁶, R¹²⁶ represents ahydrogen atom or a substituent, each R¹²⁶ may be the same as ordifferent from every other R¹²⁶, each of L¹²² and L¹²³ represents acarbon atom, a nitrogen atom, an oxygen atom or a phosphorus atom, E¹²¹represents an atomic group for forming a bidentate ligand together withL¹²² and L¹²³, k represents an integer of 1 to 3, l represents aninteger of 0 to 2, k+l is 2 or 3, each of S¹²¹ and S¹²² independentlyrepresents a group represented by formula (I), each of n and mrepresents an integer of 0 to 4, n+m is an integer of 1 to 4, and eachS¹²¹ or S¹²² may be the same as or different from every other S¹²¹ orS¹²².)[13]

The organic electroluminescence device according to [6],

wherein the metal complex represented by formula (1) is a metal complexrepresented by the following formula (13).

(In formula (13), each of A¹³¹ and A¹³² represents a nitrogen atom or acarbon atom, each of Y¹³¹ and Y¹³² represents a linking group or asingle bond, each of L¹³¹ and L¹³² represents a partial structure havingan atom bonded to Pt, each of Z¹³¹ and Z¹³² represents an aromaticnitrogen-containing heterocyclic ring, each of X¹³¹ and X¹³² representsan oxygen atom, a sulfur atom, a substituted or unsubstituted nitrogenatom or a single bond, E¹³¹ represents a divalent linking group, each ofS¹³¹ and S¹³² independently represents a group represented by formula(I), each of n and m represents an integer of 0 to 4, n+m is an integerof 1 to 4, and each S¹³¹ or S¹³² may be the same as or different fromevery other S¹³¹ or S¹³².)[14]

The organic electroluminescence device according to [13],

wherein the metal complex represented by formula (13) is represented bythe following formula (14).

(In formula (14), wherein each of A¹⁴¹ to A¹⁴⁶ independently representsa nitrogen atom or a carbon atom, each of Z¹⁴¹ and Z¹⁴² independentlyrepresents an aromatic nitrogen-containing heterocyclic ring, each ofZ¹⁴³ and Z¹⁴⁴ independently represents an aromatic heterocyclic ring oran aromatic hydrocarbon ring, E¹⁴¹ represents a divalent linking group,each of S¹⁴¹ to S¹⁴⁴ independently represents a group represented byformula (I), each of n, m, k and l represents an integer of 0 to 4,n+m+k+l is an integer of 1 to 4, and each S¹⁴¹, S¹⁴², S¹⁴³ or S¹⁴⁴ maybe the same as or different from every other S¹⁴¹, S¹⁴², S¹⁴³ or S¹⁴⁴.)[15]

The organic electroluminescence device according to [14],

wherein the metal complex represented by formula (14) is represented bythe following formula (15).

(In formula (15), each of A¹⁵¹ to A¹⁵⁴ independently represents anitrogen atom or a carbon atom, each of R¹⁵³ to R¹⁵⁸ independentlyrepresents a hydrogen atom or a substituent, each of Z¹⁵¹ and Z¹⁵²independently represents an aromatic heterocyclic ring or an aromatichydrocarbon ring, E¹⁵¹ represents a divalent linking group, each of S¹⁵¹to S¹⁵⁴ independently represents a group represented by formula (I),each of n, m, k and l represents an integer of 0 to 4, n+m+k+l is aninteger of 1 to 4, and each S¹⁵¹, S¹⁵², S¹⁵³ or S¹⁵⁴ may be the same asor different from every other S¹⁵¹, S¹⁵², S¹⁵³ or S¹⁵⁴.)[16]

The organic electroluminescence device according to [14],

wherein the metal complex represented by formula (14) is represented bythe following formula (18).

(In formula (18), each of A¹⁸¹ to A¹⁸⁶ independently represents anitrogen atom or a carbon atom, each of D¹⁸¹ to D¹⁸⁴ independentlyrepresents an atom selected from carbon, nitrogen, oxygen, sulfur andsilicon, the bond between atoms in the 5-membered ring formed by D¹⁸¹,D¹⁸², A¹⁸¹, the nitrogen atom and the carbon atom or by D¹⁸³, D¹⁸⁴,A¹⁸⁴, the nitrogen atom and the carbon atom represents a single bond ora double bond, each of D¹⁸¹ to D¹⁸⁴ when these can be furthersubstituted may have a substituent, each of Z¹⁸¹ and Z¹⁸² independentlyrepresents an aromatic heterocyclic ring or an aromatic hydrocarbonring, E¹⁸¹ represents a divalent linking group, each of S¹⁸¹ to S¹⁸⁴independently represents a group represented by formula (I), each of n,m, k and l represents an integer of 0 to 4, n+m+k+l is an integer of 1to 4, and each S¹⁸¹, S¹⁸², S¹⁸³ or S¹⁸⁴ may be the same as or differentfrom every other S¹⁸¹, S¹⁸², S¹⁸³ or S¹⁸⁴.)[17]

The organic electroluminescence device according to any one of [1] to[5],

wherein the metal complex having a group represented by formula (I) is aphosphorescent metal complex containing a monoanionic bidentate ligandrepresented by the following formulae (A1) to (A4) and a metal having anatomic weight of 40 or more.

(In formulae (A1) to (A4), each of E_(1a) to E_(1q) independentlyrepresents a carbon atom or a heteroatom, each of R_(1a) to R_(1i)independently represents a hydrogen atom or a substituent, provided thatat least one of R_(1a) to R_(1i) represents a group represented byformula (I), and each of the structures represented by formulae (A1) to(A4) has a structure with 18 π-electrons in total.)[18]

The organic electroluminescence device according to [17],

wherein said phosphorescent metal complex contains a monoanionicbidentate ligand represented by the following formula (A1-3) or (A3-3)and a metal having an atomic weight of 40 or more.

(In formulae (A1-3) to (A3-3), each of E_(1f) to E_(1k) independentlyrepresents a carbon atom or a heteroatom, each of R_(1a) to R_(1i)independently represents a hydrogen atom or a substituent, provided thatat least one of R_(1a) to R_(1i) represents a group represented byformula (I), and each of the structures represented by formulae (A1-3)and (A3-3) has a structure with 18 πt-electrons in total.)[19]

The organic electroluminescence device according to [18],

wherein said phosphorescent metal complex is an iridium complexrepresented by the following formula (A9).

(In formula (9), each of R_(1a) to R_(1i) independently represents ahydrogen atom or a substituent, provided that at least one of R_(1a) toR_(1i) represents a group represented by formula (I), X—Y represents amonoanionic bidentate ligand, and n represents an integer of 1 to 3.)[20]

The organic electroluminescence device according to any one of [1] to[19],

wherein the metal complex having a group represented by formula (I) iscontained in the light emitting layer.

[21]

The organic electroluminescence device according to any one of [1] to[20],

wherein a carbazole or indole structure-containing material is furthercontained in any one of the organic layer.

[22]

The organic electroluminescence device according to any one of [1] to[21],

wherein a carbazole or indole structure-containing material is furthercontained in the light emitting layer.

[23]

A composition containing a metal complex having a group represented byformula (I) in [1].

[24]

A light emitting layer containing a metal complex having a grouprepresented by formula (I) in [1].

[25]

A light emission apparatus using the organic electroluminescence deviceaccording to any one of [1] to [22].

[26]

A display apparatus using the organic electroluminescence deviceaccording to any one of [1] to [22].

[27]

An illumination apparatus using the organic electroluminescence deviceaccording to any one of [1] to [22].

The organic electroluminescence device of the present invention containsa metal complex having a group represented by formula (I). By thisconfiguration, an organic electroluminescence device (in the context ofthe present invention, this term is used with the same meaning as “thedevice of the present invention”) having high luminous efficiency (forexample, external quantum efficiency) and high durability and causinglittle chromaticity shift after device deterioration can be provided.Also, a long life of the device can be realized.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view showing one example of the configuration ofthe organic electroluminescence device according to the presentinvention.

FIG. 2 is a schematic view showing one example of the light emissionapparatus according to the present invention.

FIG. 3 is a schematic view showing one example of the illuminationapparatus according to the present invention.

DESCRIPTION OF EMBODIMENTS

The organic electroluminescence device of the present invention is anorganic electroluminescence device including a substrate having thereona pair of electrodes and at least one organic layer between saidelectrodes, the organic layer containing a light emitting layer, whereinany one layer of the organic layer contains a metal complex having agroup represented by the following formula (I):

(wherein R₁ represents an alkyl group, each of R₂ and R₃ independentlyrepresents a hydrogen atom or an alkyl group, n represents an integer of0 to 6, and Z represents a saturated 5- to 8-membered ring).

The metal complex having a group represented by formula (I) includes itstautomers and is a metal complex having a group containing a specificsaturated ring group. It has been considered that usually, when asecondary or tertiary carbon is substituted on an aromatic heterocyclicring or an aromatic hydrocarbon ring, a hydrogen elimination reaction ora dimerization reaction from the excited state occurs, giving rise todecrease in the device life. However, introduction of a sterically bulkygroup is expected to bring about spatial separation of reactive sites ofthe light emitting material, whereby a hydrogen elimination reaction ordimerization reaction of the metal complex is suppressed and the devicelife is prolonged.

Particularly, in an organic electroluminescence device using, as thelight emitting material, a metal complex of the present invention wherea group containing a saturated ring group having quaternary carbon in asaturated 5- to 8-membered ring group is substituted on a ligand, thatis, an aromatic heterocyclic ring or an aromatic hydrocarbon ring, thesaturated ring group is sterically bulky but is more compactly andrigidly organized as compared with a chain group having the same numberof atoms as the structure. Accordingly, the film state is considered tochange by any form while keeping an appropriate intermolecular distance,whereby the degree of order in the molecular arrangement is increased,as a result, a charge career mobility in the device using the metalcomplex is increased, and an effect such as enhancement of the deviceefficiency and reduction of the drive voltage is obtained.

Also, by the stable film structure at driving, it is presumed that themetal complex can contribute also to the enhancement of durability.

Furthermore, in the embodiment where a saturated ring group as the grouprepresented by formula (I) is combined to the ligand through asubstituted or unsubstituted methylene group, the flexibility of thegroup represented by formula (I) is increased and the dispersibility ofthe light emitting material to the organic layer is enhanced as comparedwith the conventional alkyl group-substituted phosphorescent material,as a result, interaction of light emitting material molecules with eachother is suppressed. These improved dispersibility and reducedinteraction are presumed to enable more enhancing the device efficiencyand easily obtaining an effect of reducing the chromaticity shift at thedevice deterioration.

According to the embodiment where a group represented by formula (I)having high flexibility is introduced, the solubility of thephosphorescent material in an organic solvent can be increased, and ahigh-concentration solution can be prepared. The coating step using ahigh-concentration solution is advantageous for improvement of the filmhomogeneity and reduction in impurities (dissolved oxygen, water), andan enhanced efficiency and a long life of a device fabricated by a wetprocess can be realized.

R₁ represents an alkyl group. Here, R₁ represents an alkyl group whichmay be substituted or may be linear or branched, and preferablyrepresents an alkyl group having a carbon number of 1 to 12, morepreferably from 1 to 6. R₁ is preferably an unsubstituted alkyl group,more preferably an unsubstituted linear alkyl group, still morepreferably a methyl group or an ethyl group, and most preferably amethyl group.

Each of R₂ and R₃ independently represents a hydrogen atom or an alkylgroup. Here, each of R₂ and R₃ independently represents a hydrogen atomor an alkyl group which may be substituted or may be linear or branched,and preferably represents an alkyl group having a carbon number of 1 to12, more preferably from 1 to 6. Each of R₂ and R₃ is preferably ahydrogen atom or an unsubstituted alkyl group, more preferably ahydrogen atom or an unsubstituted linear alkyl group, still morepreferably a hydrogen atom or a methyl group, yet still more preferablya hydrogen atom.

n represents an integer of 0 to 6, and n is preferably an integer of 1to 6, more preferably an integer of 1 to 3, yet still more preferably 1.

When n is 1 or more, the flexibility of the group represented by formula(I) is increased and the dispersibility of the light emitting materialto the organic layer is enhanced, as a result, interaction of lightemitting material molecules with each other is suppressed. Theseimproved dispersibility and reduced interaction are considered to enableenhancing the device efficiency and easily obtaining an effect ofreducing the chromaticity shift at the device deterioration.

Z represents a saturated 5- to 8-membered ring, more preferably a 5- or6-membered ring, together with C. The saturated 5- to 8-membered ringrepresented by Z is preferably formed of a carbon atom, a hydrogen atom,an oxygen atom, a nitrogen atom and a sulfur atom, more preferablyformed of a carbon atom, a hydrogen atom and an oxygen atom, still morepreferably formed of a carbon atom and a hydrogen atom.

Preferred examples of the saturated 5- to 8-membered ring represented byZ include a cyclopentane ring, a cyclohexane ring, a cycloheptane ring,a cyclooctane ring, a tetrahydrofuran ring, a tetrahydropyran ring, atetrahydrothiophene ring, a dioxane ring, a pyrrolidine ring, apiperidine ring, a piperazine ring and a morpholine ring. Among these, acyclopentane ring, a cyclohexane ring, a cycloheptane ring and acyclooctane ring are more preferred, and a cyclopentane ring and acyclohexane ring are still more preferred.

The saturated 5- to 8-membered ring is generally excellent in thechemical stability as compared with a saturated 3- or 4-membered ringand therefore, the device of the present invention using a lightemitting material having a group represented by formula (I) isconsidered to be excellent in the drive durability as compared with adevice using a light emitting layer having a substituent containing asaturated 3- or 4-membered ring. Also, thanks to the bulky and rigidstructure, the effect by the enhanced degree of order in the arrangementis considered to be great.

Furthermore, the group represented by formula (I) has a quaternarycarbon atom in the saturated ring group and therefore, is bulky as wellas rigid, and this is presumed to make larger the effect by the enhanceddegree of order and enable obtaining an effect in terms of enhancementof the device efficiency, reduction of the drive voltage and improvementof the durability.

The saturated 5- to 8-membered ring represented by Z may further have asubstituent thereon. Preferred examples of this substituent include analkyl group, a cycloalkyl group and an aryl group.

Substituents a1 to a31 are illustrated below as preferred examples ofthe group represented by formula (I), but the present invention is notlimited thereto.

Among these, a1, a2, a3, a5, a8, a9, a10, a12, a14, a15, a18, a19, a28,a29, a30 and a31 are preferred, a2, a5, a9, a12, a18, a19, a28 and a29are more preferred, and a2, a5, a9 and a12 are still more preferred.

[Compound Represented by Formula (1)]

The compound represented by formula (1) is described in detail.

(In formula (1), M¹¹ represents a metal belong to Groups 8 to 11 in theperiodic table of elements, A¹¹ represents a nitrogen atom or a carbonatom, X¹¹ represents an oxygen atom, a sulfur atom, a substituted orunsubstituted nitrogen atom or a single bond, Y¹¹ represents a linkinggroup or a single bond, L¹¹ represents a partial structure having anatom bonded to X¹¹, Z¹¹ represents an aromatic nitrogen-containingheterocyclic ring, each of L¹² and L¹³ represents a carbon atom, anitrogen atom, an oxygen atom or a phosphorus atom, E¹¹ represents anatomic group for forming a bidentate ligand together with L¹² and L¹³, krepresents an integer of 1 to 3, l represents an integer of 0 to 2, k+lis 2 or 3, each S¹¹ independently represents a group represented byformula (I), n represents an integer of 1 to 4, and each S¹¹ may be thesame as or different from every other S¹¹).

M¹¹ represents a metal (may be a metal atom or ion) belonging to Groups8 to 11 in the periodic table of elements and is preferably gold,copper, platinum, palladium, nickel, iridium rhodium, osmium orruthenium, more preferably gold, platinum, palladium iridium orruthenium, still more preferably gold, platinum, palladium or iridium,and most preferably platinum or iridium.

A¹¹ represents a nitrogen atom or a carbon atom and forms an aromaticnitrogen-containing heterocyclic ring together with the N atom and Z¹¹.

Examples of the aromatic nitrogen-containing heterocyclic ringrepresented by Z¹¹ in formula (1) include a pyridine ring, a pyridazinering, a pyrimidine ring, a pyrazine ring, a triazine ring, abenzimidazole ring, an oxadiazole ring, a triazole ring, an imidazolering, a pyrazole ring, a thiazole ring, an oxazole ring, a benzimidazolering, a benzothiazole ring, a benzoxazole ring, an isoquinoline ring, aquinoxaline ring, a quinazoline ring, a phthalazine ring, a carbolinering, and a ring where a carbon atom of a hydrocarbon ring constitutinga carboline ring is further substituted with a nitrogen atom.

Z¹¹ is preferably a pyridine ring, a pyrimidine ring, a pyrazine ring, abenzimidazole ring, an oxadiazole ring, a triazole ring, an imidazolering, a pyrazole ring, a thiazole ring, an oxazole ring, a benzimidazolering, a benzothiazole ring, a benzoxazole ring, an isoquinoline ring ora quinoxaline ring, more preferably a pyridine ring, a pyrimidine ring,a pyrazine ring, an imidazole ring, a pyrazole ring, an isoquinolinering or a quinoxaline ring, still more preferably an isoquinoline ring,a benzoxazole ring, a pyridine ring, an imidazole ring or a pyrazolering.

The aromatic nitrogen-containing heterocyclic ring may have asubstituent, and those described below as Substituent Group A can beapplied to the substituent.

(Substituent Group A)

An alkyl group (preferably having a carbon number of 1 to 30, morepreferably from 1 to 20, still more preferably from 1 to 10, e.g.,methyl, ethyl, isopropyl, tert-butyl, n-octyl, n-decyl, n-hexadecyl,trifluoromethyl, pentafluoroethyl), a cycloalkyl group (preferablyhaving a carbon number of 3 to 30, more preferably from 3 to 20, stillmore preferably from 3 to 10, e.g., cyclopropyl, cyclopentyl,cyclohexyl), an alkenyl group (preferably having a carbon number of 2 to30, more preferably from 2 to 20, still more preferably from 2 to 10,e.g., vinyl, allyl, 2-butenyl, 3-pentenyl), an alkynyl group (preferablyhaving a carbon number of 2 to 30, more preferably from 2 to 20, stillmore preferably from 2 to 10, e.g., propargyl, 3-pentynyl),

an aryl group (preferably having a carbon number of 6 to 30, morepreferably from 6 to 20, still more preferably from 6 to 12, e.g.,phenyl, p-methylphenyl, naphthyl, anthranyl), an amino group (preferablyhaving a carbon number of 0 to 30, more preferably from 0 to 20, stillmore preferably from 0 to 10, e.g., amino, methylamino, dimethylamino,diethylamino, dibenzylamino, diphenylamino, ditolylamino), an alkoxygroup (preferably having a carbon number of 1 to 30, more preferablyfrom 1 to 20, still more preferably from 1 to 10, e.g., methoxy, ethoxy,butoxy, 2-ethylhexyloxy), an aryloxy group (preferably having a carbonnumber of 6 to 30, more preferably from 6 to 20, still more preferablyfrom 6 to 12, e.g., phenyloxy, 1-naphthyloxy, 2-naphthyloxy), aheterocyclic oxy group (preferably having a carbon number of 1 to 30,more preferably from 1 to 20, still more preferably from 1 to 12, e.g.,pyridyloxy, pyrazyloxy, pyrimidyloxy, quinolyloxy),

an acyl group (preferably having a carbon number of 1 to 30, morepreferably from 1 to 20, still more preferably from 1 to 12, e.g.,acetyl, benzoyl, formyl, pivaloyl), an alkoxycarbonyl group (preferablyhaving a carbon number of 2 to 30, more preferably from 2 to 20, stillmore preferably from 2 to 12, e.g., methoxycarbonyl, ethoxycarbonyl), anaryloxycarbonyl group (preferably having a carbon number of 7 to 30,more preferably from 7 to 20, still more preferably from 7 to 12, e.g.,phenyloxycarbonyl), an acyloxy group (preferably having a carbon numberof 2 to 30, more preferably from 2 to 20, still more preferably from 2to 10, e.g., acetoxy, benzoyloxy), an acylamino group (preferably havinga carbon number of 2 to 30, more preferably from 2 to 20, still morepreferably from 2 to 10, e.g., acetylamino, benzoylamino),

an alkoxycarbonylamino group (preferably having a carbon number of 2 to30, more preferably from 2 to 20, still more preferably from 2 to 12,e.g., methoxycarbonylamino), an aryloxycarbonylamino group (preferablyhaving a carbon number of 7 to 30, more preferably from 7 to 20, stillmore preferably from 7 to 12, e.g., phenyloxycarbonylamino), asulfonylamino group (preferably having a carbon number of 1 to 30, morepreferably from 1 to 20, still more preferably from 1 to 12, e.g.,methanesulfonylamino, benzenesulfonylamino), a sulfamoyl group(preferably having a carbon number of 0 to 30, more preferably from 0 to20, still more preferably from 0 to 12, e.g., sulfamoyl,methylsulfamoyl, dimethylsulfamoyl, phenylsulfamoyl),

a carbamoyl group (preferably having a carbon number of 1 to 30, morepreferably from 1 to 20, still more preferably from 1 to 12, e.g.,carbamoyl, methylcarbamoyl, diethylcarbamoyl, phenylcarbamoyl), analkylthio group (preferably having a carbon number of 1 to 30, morepreferably from 1 to 20, still more preferably from 1 to 12, e.g.,methylthio, ethylthio), an arylthio group (preferably having a carbonnumber of 6 to 30, more preferably from 6 to 20, still more preferablyfrom 6 to 12, e.g., phenylthio), a heterocyclic thio group (preferablyhaving a carbon number of 1 to 30, more preferably from 1 to 20, stillmore preferably from 1 to 12, e.g., pyridylthio, 2-benzimizolylthio,2-benzoxazolylthio, 2-benzothiazolylthio),

a sulfonyl group (preferably having a carbon number of 1 to 30, morepreferably from 1 to 20, still more preferably from 1 to 12, e.g.,mesyl, tosyl), a sulfonyl group (preferably having a carbon number of 1to 30, more preferably from 1 to 20, still more preferably from 1 to 12,e.g., methanesulfinyl, benzenesulfinyl), a ureido group (preferablyhaving a carbon number of 1 to 30, more preferably from 1 to 20, stillmore preferably from 1 to 12, e.g., ureido, methylureido, phenylureido),a phosphoric acid amido group (preferably having a carbon number of 1 to30, more preferably from 1 to 20, still more preferably from 1 to 12,e.g., diethylphosphoric acid amido, phenylphosphoric acid amido), ahydroxy group, a mercapto group, a halogen atom (for example, a fluorineatom, a chlorine atom, a bromine atom and an iodine atom, preferably afluorine atom),

a cyano group, a sulfo group, a carboxyl group, a nitro group, ahydroxamic acid group, a sulfino group, a hydrazino group, an iminogroup, a heterocyclic group (preferably having a carbon number of 1 to30, more preferably from 1 to 12; examples of the heteroatom include anitrogen atom, an oxygen atom and a sulfur atom; specifically animidazolyl group, a pyridyl group, a quinolyl group, a furyl group, athienyl group, a piperidyl group, a morpholino group, a benzoxazolylgroup, a benzimidazolyl group, a benzothiazolyl group, a carbazolylgroup, an azepinyl group and the like), a silyl group (preferably havinga carbon number of 3 to 40, more preferably from 3 to 30, still morepreferably from 3 to 24, e.g., trimethylsilyl, triphenylsilyl), and asilyloxy group (preferably having a carbon number of 3 to 40, morepreferably from 3 to 30, still more preferably from 3 to 24, e.g.,trimethylsilyloxy, triphenylsilyloxy). These substituents may be furthersubstituted.

Also, a plurality of these substituents may combine with each other toform a ring.

The substituent of the aromatic nitrogen-containing heterocyclic ring ispreferably a substituted or unsubstituted alkyl group, a cycloalkylgroup, an aryl group, an amino group, an alkoxy group, an aryloxy group,an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, anacyloxy group, a sulfonylamino group, a sulfamoyl group, a carbamoylgroup, an alkylthio group, an arylthio group, a heterocyclic thio group,a sulfonyl group, a sulfinyl group, a ureido group, a phosphoric acidamido group, a hydroxy group, a mercapto group, a halogen atom, a sulfogroup, a carboxyl group, a nitro group, a sulfino group, a heterocyclicgroup or a silyl group, more preferably a substituted or unsubstitutedalkyl group, a cycloalkyl group, an aryl group, an amino group, analkoxy group, an aryloxy group, a cyano group, a fluorine atom or aheterocyclic group, still more preferably a substituted or unsubstitutedalkyl group, a fluorine atom, a methoxy group, an aryl group or a cyanogroup. In particular, the substituent is preferably a substituted orunsubstituted alkyl group, a fluorine atom or a cyano group, and mostpreferably a methyl group, a trifluoromethyl group, a fluorine atom or acyano group.

X¹¹ represents an oxygen atom, a sulfur atom, a substituted orunsubstituted nitrogen atom or a single bond and is preferably an oxygenatom, a sulfur atom or a single bond, more preferably an oxygen atom ora single bond, still more preferably a single bond. In the case whereX¹¹ represents a substituted nitrogen atom, the substituent is, forexample, preferably a substituent selected from Substituent Group A,more preferably an alkyl group, a cycloalkyl group or an aryl group,still more preferably an alkyl group having a carbon number of 1 to 7 oran aryl group having a carbon number of 6 to 12 (number of ring members:from 1 to 2).

Y¹¹ represents a linking group or a single bond. The linking group isnot particularly limited but is preferably a single bond or a divalentlinking group containing a carbon atom, a nitrogen atom, an oxygen atom,a sulfur atom, a silicon atom, a germanium atom or a phosphorus atom,more preferably a single bond or a group selected from Linking Group Ashown below.

Linking Group A:

In Linking Group A, each of R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹, R¹⁰, R¹¹and R¹² (R¹ to R¹²) independently represents a hydrogen atom or asubstituent selected from substituents including Substituent Group A. Inthe case where each of R¹ to R¹² represents a substituent, thesubstituent is preferably a substituent selected from Substituent GroupA. Each of R¹ to R¹² when these can be substituted may further have asubstituent, and R¹ and R², R³ and R⁴, R⁵ and R⁶, R³ and R⁵, R³ and R⁶,R⁴ and R⁶, or R¹⁰ and R¹¹ may combine with each other to form a ring.

Y¹¹ is more preferably a single bond or a substituent selected fromLinking Group A. Among these, a single bond, —C(R¹)(R²)—,—C(R³)(R⁴)C(R⁵)(R⁶)—, —Si(R⁷)(R⁸)—, —N(R⁹)—, —O—, —S—, —SO—, —SO₂— and—CO— are preferred, a single bond, —C(R¹)(R²)—, —C(R³)(R⁴)C(R⁵)(R⁶)—,—Si(R⁷)(R⁸)—, —O— and —S— are more preferred, a single bond —C(R′)(R²)—and —C(R³)(R⁴)C(R⁵)(R⁶)— are still more preferred, and a single bond isyet still more preferred.

In —C(R¹)(R²)—, each of R¹ and R² is preferably a hydrogen atom or asubstituent selected from Substituent Group B below.

(Substituent Group B)

The substituent includes an alkyl group, a cycloalkyl group, an arylgroup, a halogen atom, an amino group, an alkylthio group, an arylthiogroup, an alkyloxy group, an aryloxy group, a hydroxy group, a mercaptogroup and a halogen atom. Among these, an alkyl group, a cycloalkylgroup, an aryl group, a halogen atom, an alkylthio group, an arylthiogroup, an alkyloxy group, an aryloxy group and a halogen atom arepreferred, and an alkyl group and an aryl group are more preferred.

In —C(R³)(R⁴)C(R⁵)(R⁶)—, each of R³, R⁴, R⁵ and R⁶ is preferably ahydrogen atom or a substituent selected from Substituent Group B.

In —Si(R⁷)(R⁸)—, each of R⁷ and R⁸ is preferably a hydrogen atom or asubstituent selected from Substituent Group B.

In —Ge(R¹⁰)(R¹¹)—, each of R¹⁰ and R¹¹ is preferably a hydrogen atom ora substituent selected from Substituent Group B.

In —N(R⁹)—, R⁹ is preferably a hydrogen atom, an alkyl group, acycloalkyl group or an aryl group, more preferably an alkyl group or anaryl group, still more preferably an aryl group.

In —P(R¹²)—, R¹² has the same meaning as the preferred range of R⁹.

In formula (1), L¹ represents a partial structure having an atom bondedto X¹¹. The partial structure of L¹¹ is preferably a group bondedthrough a carbon atom, a group bonded through a nitrogen atom, a groupbonded through a silicon atom, a group bonded through a phosphorus atom,a group bonded through an oxygen atom, or a group bonded through asulfur atom, more preferably a group bonded through a carbon atom, anitrogen atom, an oxygen atom or a sulfur atom, still more preferably agroup bonded through a carbon atom or an oxygen atom.

The group bonded through a carbon atom is preferably a substituted orunsubstituted aryl group bonded through a carbon atom, a substituted orunsubstituted 5-membered heteroaryl group bonded through a carbon atom,or a substituted or unsubstituted 6-membered heteroaryl group bondedthrough a carbon atom, more preferably a substituted or unsubstitutedaryl group bonded through a carbon atom, a substituted or unsubstitutednitrogen-containing 5-membered heteroaryl group bonded through a carbonatom, or a nitrogen-containing 6-membered heteroaryl group bondedthrough a carbon atom, still more preferably a substituted aryl groupbonded through a carbon atom.

The group bonded through an oxygen atom is preferably a substituted orunsubstituted hydroxyl group or a substituted or unsubstituted carboxylgroup, more preferably a substituted or unsubstituted carboxyl group.

The group bonded through a nitrogen atom is preferably a substitutedamino group or a nitrogen-containing 5-membered heteroaryl group bondedthrough a nitrogen atom, more preferably a nitrogen-containing5-membered heteroaryl group bonded through a nitrogen atom, still morepreferably a substituted carbazole group, a substituted pyrrole group ora substituted indole group.

The group bonded through a phosphorus atom is preferably a substitutedphosphino group. The group bonded through a silicon atom is preferably asubstituted silyl group. The group bonded through a sulfur atom ispreferably a thiol group or a substituted thiol group.

Each of L¹² and L¹³ represents a carbon atom, a nitrogen atom, an oxygenatom or a phosphorus atom, and E¹¹ represents an atomic group forforming a bidentate ligand together with L¹² and L¹³. The combination ofL¹² and L¹³ is not particularly limited but is preferably nitrogenatom-carbon atom, nitrogen atom-oxygen atom, or oxygen atom-oxygen atom.The bidentate ligand represented by L¹²-E¹¹-L¹³ is not particularlylimited, but specific examples thereof include substituted orunsubstituted phenylpyridine, phenylpyrazole, phenylimidazole,phenyltriazole, phenyltetrazole, pyridylpyridine, imidazolylpyridine,pyrazolylpyridine, triazolylpyridine, pyrazabole,diphenylphosphinoethylene, picolinic acid and acetylacetone. Amongthese, phenylpyridine, phenylpyrazole, phenylimidazole, pyridylpyridine,pyrazabole, picolinic acid and acetylacetone are preferred, andphenylpyridine, pyridylpyridine, picolinic acid and acetylacetone aremore preferred. These groups may be further substituted with theabove-described substituent.

k represents an integer of 1 to 3, l represents an integer of 0 to 2,and k+l is 2 or 3. l is preferably 1 or 0, more preferably 0.

S¹¹ represents a group represented by formula (I).

As the group represented by formula (I), substituents a1 to a31 arepreferred, a1, a2, a3, a5, a8, a9, a10, a12, a14, a15, a18, a19, a28,a29, a30 and a31 are more preferred, a2, a5, a9, a12, a18, a19, a28 anda29 are still more preferred, and a2, a5, a9 and a12 are most preferred.This is presumed because all of bulkiness, rigidity and compactness aresatisfied.

The group represented by formula (I) contains a quaternarycarbon-containing saturated ring group in a saturated 5- to 8-memberedring and therefore, is sterically bulky but is more compactly andrigidly organized as compared with a chain group having the same numberof atoms as the framework. Accordingly, the film state is considered tochange by any form while keeping an appropriate intermolecular distance,whereby the degree of order in the molecular arrangement is increased,as a result, the device using, as the light emitting material, the metalcomplex having a group represented by formula (I) allows easy flow of acurrent, and an effect such as enhancement of the device efficiency andreduction of the drive voltage is obtained. Furthermore, thanks to thestable film structure at driving, it is presumed that the metal complexcan contribute also to the enhancement of durability.

In addition, the saturated 5- to 8-membered ring is generally excellentin the chemical stability as compared with a saturated 3- or 4-memberedring and therefore, the device of the present invention using a lightemitting material having a group represented by formula (I) isconsidered to be excellent in the drive durability as compared with adevice using a light emitting layer having a substituent containing asaturated 3- or 4-membered ring. Also, thanks to the bulky and rigidstructure, the effect by the enhanced degree of order in the arrangementis considered to be great.

n represents an integer of 1 to 4. n is preferably 1 or 2.

The compound represented by formula (1) is preferably represented by thefollowing formula (2):

(In formula (2), M²¹ represents a metal belong to Groups 8 to 11 in theperiodic table of elements, each of A²¹ to A²³ independently representsa nitrogen atom or a carbon atom, Z²¹ represents an aromaticnitrogen-containing heterocyclic ring, Z²² represents an aromaticheterocyclic ring or an aromatic hydrocarbon ring, each of L²² and L²³represents a carbon atom, a nitrogen atom, an oxygen atom or aphosphorus atom, E²¹ represents an atomic group for forming a bidentateligand together with L²² and L²³, k represents an integer of 1 to 3, lrepresents an integer of 0 to 2, k+l is 2 or 3, each of S²¹ and S²²independently represents a group represented by formula (I), each of nand m represents an integer of 0 to 4, n+m is an integer of 1 to 4, andeach S²¹ or S²² may be the same as or different from every other S²¹ orS²²).

In formula (2), M²¹, A²¹, A²¹, Z²¹, L²², L²³, L²³, E²¹, S²¹, S²², Informula (2), k and l have the same meanings as M¹¹, A¹¹, Z¹¹, L¹², L¹³,E¹¹, S¹¹, k and l in formula (1), and the preferred ranges are also thesame.

Each of A²² and A²³ represents a nitrogen atom or a carbon atom, andthese form an aromatic heterocyclic ring or an aromatic hydrocarbon ringtogether with Z²².

Examples of the aromatic heterocyclic ring or aromatic hydrocarbon ringrepresented by Z²² include a benzene ring, a naphthalene ring, ananthracene ring, a pyrene ring, a phenanthrene ring, a perylene ring, apyridine ring, a quinoline ring, an isoquinoline ring, a phenanthridinering, a pyrimidine ring, a pyrazine ring, a pyridazine ring, a triazinering, a cinnoline ring, an acridine ring, a phthalazine ring, aquinazoline ring, a quinoxaline ring, a naphthyridine ring, a pteridinering, a pyrrole ring, a pyrazole ring, a triazole ring, an indole ring,a carbazole ring, an indazole ring, a benzimidazole ring, an oxazolering, a thiazole ring, an oxadiazole ring, a thiadiazole ring, abenzoxazole ring, a benzothiazole ring, an imidazopyridine ring, athiophene ring, a benzothiophene ring, a furan ring, a benzofuran ring,a phosphole ring, a phosphinine ring and a silole ring.

Z²² is preferably a benzene ring, a naphthalene ring, a benzoxazolering, a pyrazole ring, an imidazole ring, a triazole ring, a pyridinering, an indole ring or a thiophene ring, more preferably a benzenering, a pyrazole ring, a pyridine ring, a benzoxazole ring or athiophene ring.

Z²² may have a substituent, and those described above as SubstituentGroup A can be applied to the substituent. Furthermore, Z²² may form acondensed ring with other rings.

This substituent is preferably a substituted or unsubstituted alkylgroup, a cycloalkyl group, an aryl group, an amino group, an alkoxygroup, an aryloxy group, an acyl group, an alkoxycarbonyl group, anaryloxycarbonyl group, an acyloxy group, a sulfonylamino group, asulfamoyl group, a carbamoyl group, an alkylthio group, an arylthiogroup, a heterocyclic thio group, a sulfonyl group, a sulfonyl group, aureido group, a phosphoric acid amido group, a hydroxy group, a mercaptogroup, a halogen atom, a sulfo group, a carboxyl group, a nitro group, asulfino group, a heterocyclic group or a silyl group, more preferably asubstituted or unsubstituted alkyl group, a cycloalkyl group, an arylgroup, an amino group, an alkoxy group, an aryloxy group, a cyano group,a fluorine atom or a heterocyclic group, still more preferably asubstituted or unsubstituted alkyl group, a fluorine atom, a methoxygroup, an aryl group or a cyano group. In particular, the substituent ispreferably a substituted or unsubstituted alkyl group, a fluorine atomor a cyano group, and most preferably a methyl group, a trifluoromethylgroup, a fluorine atom or a cyano group.

Each of n and m represents an integer of 0 to 4, and n+m is an integerof 1 to 4. n+m is preferably 1 or 2.

The compound represented by formula (2) is preferably represented by thefollowing formula (3):

(In formula (3), M³¹ represents a metal belong to Groups 8 to 11 in theperiodic table of elements, each of A³¹ and A³² independently representsa nitrogen atom or a carbon atom, each of R³³ to R³⁶ independentlyrepresents a hydrogen atom or a substituent, Z³² represents an aromaticheterocyclic ring or an aromatic hydrocarbon ring, each of L³² and L³³independently represents a carbon atom, a nitrogen atom, an oxygen atomor a phosphorus atom, E³¹ represents an atomic group for forming abidentate ligand together with L³² and L³³, k represents an integer of 1to 3, l represents an integer of 0 to 2, k+l is 2 or 3, each of S³¹ andS³² independently represents a group represented by formula (I), each ofn and m represents an integer of 0 to 4, n+m is an integer of 1 to 4,and each S³¹ or S³² may be the same as or different from every other S³¹or S³²).

In formula (3) M³¹, A³¹, A³², Z³², L³², L³³, E³¹, S³¹, S³², n, m, k andl have the same meanings as M²¹, A²², A²³, Z²², L²², L²³, E²¹, S²¹, S²²,n, m, k and l in formula (2), and the preferred ranges are also thesame.

Each of R³³ to R³⁶ independently represents a hydrogen atom or asubstituent selected from substituents including Substituent Group A.The substituent is preferably a substituted or unsubstituted alkylgroup, a cycloalkyl group, an aryl group, an amino group, an alkoxygroup, an aryloxy group, an acyl group, an alkoxycarbonyl group, anaryloxycarbonyl group, an acyloxy group, a sulfonylamino group, asulfamoyl group, a carbamoyl group, an alkylthio group, an arylthiogroup, a heterocyclic thio group, a sulfonyl group, a sulfinyl group, aureido group, a phosphoric acid amido group, a hydroxy group, a mercaptogroup, a halogen atom, a sulfo group, a carboxyl group, a nitro group, asulfino group, a heterocyclic group or a silyl group, more preferably asubstituted or unsubstituted alkyl group, a cycloalkyl group, an arylgroup, an amino group, an alkoxy group, an aryloxy group, a cyano group,a fluorine atom or a heterocyclic group, still more preferably asubstituted or unsubstituted alkyl group, a fluorine atom, a methoxygroup, an aryl group or a cyano group. In particular, the substituent ispreferably a substituted or unsubstituted alkyl group, a fluorine atomor a cyano group, and most preferably a methyl group, a trifluoromethylgroup, a fluorine atom or a cyano group.

The compound represented by formula (3) is preferably represented by thefollowing formula (4):

(In formula (4), M⁴¹ represents a metal belong to Groups 8 to 11 in theperiodic table of elements, each of R⁴³ to R⁴⁶ independently representsa hydrogen atom or a substituent, each of B⁴¹ to B⁴⁴ independentlyrepresents a nitrogen atom or C—R⁴⁷, R⁴⁷ represents a hydrogen atom or asubstituent, each R⁴⁷ may be the same as or different from every otherR⁴⁷, each of L⁴² and L⁴³ represents a carbon atom, a nitrogen atom, anoxygen atom or a phosphorus atom, E⁴¹ represents an atomic group forforming a bidentate ligand together with L⁴² and L⁴³, k represents aninteger of 1 to 3, l represents an integer of 0 to 2, k+l is 2 or 3,each of S⁴¹ and S⁴² independently represents a group represented byformula (I), each of n and m represents an integer of 0 to 4, n+m is aninteger of 1 to 4, and each S⁴¹ or S⁴² may be the same as or differentfrom every other S⁴¹ or S⁴²).

In formula (4), M⁴¹, R⁴³ to R⁴⁶, L⁴², L⁴³, E⁴¹, S⁴¹, S⁴², n, m, k and lhave the same meanings as M³¹, R³³ to R³⁶, L³², L³³, E³¹, S³¹, S³², n,m, k and l in formula (3), and the preferred ranges are also the same.

Each of B⁴¹ to B⁴⁴ independently represents a nitrogen atom or C—R⁴⁷,and R⁴⁷ represents a hydrogen atom or a substituent. The combination ofB⁴¹ to B⁴⁴ is not particularly limited but out of B⁴¹ to B⁴⁴, the numberof nitrogen atoms is preferably from 0 to 2, more preferably from 0 to1.

As for the substituent represented by R⁴⁷, those described above asSubstituent Group A can be applied.

Each R⁴⁷ may be the same as or different from every other R⁴⁷. R⁴⁷ mayfurther have a substituent, and those described above as SubstituentGroup A can be applied to the substituent. Also, R⁴⁷'s may combine witheach other to form a condensed ring, and examples of the ring formedinclude a benzene ring, a pyridine ring, a pyrazine ring, a pyrimidinering, a triazine ring, a pyridazine ring, a pyrrole ring, a pyrazolering, an imidazole ring, a triazole ring, an oxazole ring, an oxadiazolering, a thiazole ring, a thiadiazole ring, a furan ring, a thiophenering, a selenophene ring, a silole ring, a germole ring and a phospholering.

R⁴⁷ is preferably a substituted or unsubstituted alkyl group, acycloalkyl group, an aryl group, an amino group, an alkoxy group, anaryloxy group, an acyl group, an alkoxycarbonyl group, anaryloxycarbonyl group, an acyloxy group, a sulfonylamino group, asulfamoyl group, a carbamoyl group, an alkylthio group, an arylthiogroup, a heterocyclic thio group, a sulfonyl group, a sulfinyl group, aureido group, a phosphoric acid amido group, a hydroxy group, a mercaptogroup, a halogen atom, a sulfo group, a carboxyl group, a nitro group, asulfino group, a heterocyclic group or a silyl group, more preferably asubstituted or unsubstituted alkyl group, a cycloalkyl group, an arylgroup, an amino group, an alkoxy group, an aryloxy group, a cyano group,a fluorine atom or a heterocyclic group, still more preferably asubstituted or unsubstituted alkyl group, a fluorine atom, a methoxygroup, an aryl group or a cyano group. In particular, the substituent ispreferably a substituted or unsubstituted alkyl group, a fluorine atomor a cyano group, and most preferably a methyl group, a trifluoromethylgroup, a fluorine atom or a cyano group.

The compound represented by formula (4) is preferably represented by thefollowing formula (5):

(In formula (5), M⁵¹ represents a metal belong to Groups 8 to 11 in theperiodic table of elements, each of R⁵³ to R⁵⁹ and R⁵¹⁰ independentlyrepresents a hydrogen atom or a substituent, each of L⁵² and L⁵³represents a carbon atom, a nitrogen atom, an oxygen atom or aphosphorus atom, E⁵¹ represents an atomic group for forming a bidentateligand together with L⁵² and L⁵³, k represents an integer of 1 to 3, lrepresents an integer of 0 to 2, k+l is 2 or 3, each of S⁵¹ and S⁵²independently represents a group represented by formula (I), each of nand m represents an integer of 0 to 4, n+m is an integer of 1 to 4, andeach S⁵¹ or S⁵² may be the same as or different from every other S⁵¹ orS⁵²).

In formula (5), M⁵¹, L⁵², L⁵³, E⁵¹, S⁵¹, S⁵², k and l have the samemeanings as M⁴¹, L⁴², L⁴³, E⁴¹, S⁴¹, k and l in formula (4), and thepreferred ranges are also the same.

Each of R⁵³ to R⁵⁹ and R⁵¹⁰ independently represents a hydrogen atom ora substituent selected from substituents including Substituent Group A.The substituent is preferably an alkyl group, a cycloalkyl group, anaryl group, an amino group, an alkoxy group, an aryloxy group, an acylgroup, an alkoxycarbonyl group, an aryloxycarbonyl group, an acyloxygroup, a sulfonylamino group, a sulfamoyl group, a carbamoyl group, analkylthio group, an arylthio group, a heterocyclic thio group, asulfonyl group, a sulfinyl group, a ureido group, a phosphoric acidamido group, a hydroxy group, a mercapto group, a halogen atom, a sulfogroup, a carboxyl group, a nitro group, a sulfino group, a heterocyclicgroup or a silyl group, more preferably a substituted or unsubstitutedalkyl group, a cycloalkyl group, an aryl group, an amino group, analkoxy group, an aryloxy group, a cyano group, a fluorine atom or aheterocyclic group, still more preferably a substituted or unsubstitutedalkyl group, a fluorine atom, a methoxy group, an aryl group or a cyanogroup. In particular, the substituent is preferably a substituted orunsubstituted alkyl group, a fluorine atom or a cyano group, and mostpreferably a methyl group, a trifluoromethyl group, a fluorine atom or acyano group.

Each of n and m represents an integer of 0 to 4, and n+m is an integerof 1 to 4. n+m is preferably 1 or 2.

One preferred embodiment of formula (5) is represented by formula (5-1):

(In formula (5-1), M⁵¹¹ represents a metal belong to Groups 8 to 11 inthe periodic table of elements, each of R⁵¹³ to R⁵¹¹⁴ independentlyrepresents a hydrogen atom or a substituent, each of S⁵¹¹ and S⁵¹²independently represents a group represented by formula (I), each of nand m represents an integer of 0 to 4, n+m is an integer of 1 to 4, andeach S⁵¹¹ or S⁵¹² may be the same as or different from every other S⁵¹¹or S⁵¹²).

In formula (5-1), M⁵¹¹, R⁵¹³ to R⁵¹⁶, R⁵¹⁷ to R⁵¹¹⁰, S⁵¹¹, S⁵¹², n and mhave the same meanings as M⁵¹, R⁵³ to R⁵⁶, R⁵⁷ to R⁵¹⁰, S⁵¹, S⁵², n andm in formula (5), and the preferred ranges are also the same.

Each of R⁵¹¹¹ to R⁵¹¹⁴ independently represents a hydrogen atom or asubstituent selected from substituents including Substituent Group A.The substituent is preferably an alkyl group, a cycloalkyl group, anaryl group, an amino group, an alkoxy group, an aryloxy group, an acylgroup, an alkoxycarbonyl group, an aryloxycarbonyl group, an acyloxygroup, a sulfonylamino group, a sulfamoyl group, a carbamoyl group, analkylthio group, an arylthio group, a heterocyclic thio group, asulfonyl group, a sulfinyl group, a ureido group, a phosphoric acidamido group, a hydroxy group, a mercapto group, a halogen atom, a sulfogroup, a carboxyl group, a nitro group, a sulfino group, a heterocyclicgroup or a silyl group, more preferably a substituted or unsubstitutedalkyl group, a cycloalkyl group, an aryl group, an amino group, analkoxy group, an aryloxy group, a cyano group, a fluorine atom or aheterocyclic group, still more preferably a substituted or unsubstitutedalkyl group, a fluorine atom, a methoxy group, an aryl group or a cyanogroup. In particular, the substituent is preferably a substituted orunsubstituted alkyl group, a fluorine atom or a cyano group, and mostpreferably a methyl group, a trifluoromethyl group, a fluorine atom or acyano group.

Each of R⁵¹¹¹ to R⁵¹¹⁴ is preferably a hydrogen atom.

One preferred embodiment of formula (5) is represented by formula (5-2):

(In formula (5-2), M⁵²¹ represents a metal belong to Groups 8 to 11 inthe periodic table of elements, each of R⁵²³ to R⁵²¹³ independentlyrepresents a hydrogen atom or a substituent, each of S⁵²¹ and S⁵²²independently represents a group represented by formula (I), each of nand m represents an integer of 0 to 4, n+m is an integer of 1 to 4, andeach S⁵²¹ or S⁵²² may be the same as or different from every other S⁵²¹or S⁵²²).

In formula (5-2), M⁵²¹, R⁵²³ to R⁵²⁶, R⁵²⁷ to R⁵²¹⁰, S⁵²¹, S⁵²², n and mhave the same meanings as M⁵¹, R⁵³ to R⁵⁶, R⁵⁷ to R⁵¹⁰, S⁵¹, S⁵², n andm in formula (5), and the preferred ranges are also the same.

Each of R⁵²¹¹ to R⁵²¹³ independently represents a hydrogen atom or mayhave a substituent selected from substituents including SubstituentGroup A. The substituent is preferably a substituted or unsubstitutedalkyl group, a cycloalkyl group, an aryl group, an amino group, analkoxy group, an aryloxy group, an acyl group, an alkoxycarbonyl group,an aryloxycarbonyl group, an acyloxy group, a sulfonylamino group, asulfamoyl group, a carbamoyl group, an alkylthio group, an arylthiogroup, a heterocyclic thio group, a sulfonyl group, a sulfinyl group, aureido group, a phosphoric acid amido group, a hydroxy group, a mercaptogroup, a halogen atom, a sulfo group, a carboxyl group, a nitro group, asulfino group, a heterocyclic group or a silyl group, more preferably asubstituted or unsubstituted alkyl group, a cycloalkyl group, an arylgroup, an amino group, an alkoxy group, an aryloxy group, a cyano group,a fluorine atom or a heterocyclic group, still more preferably asubstituted or unsubstituted alkyl group, a fluorine atom, a methoxygroup, an aryl group or a cyano group. In particular, the substituent ispreferably a substituted or unsubstituted alkyl group, a fluorine atomor a cyano group, and most preferably a methyl group, a trifluoromethylgroup, a fluorine atom or a cyano group.

Each of R⁵²¹¹ to R⁵²¹³ is preferably a hydrogen atom, a methyl group ora tert-butyl group.

One preferred embodiment of formula (5) is represented by formula (5-3):

(In formula (5-3), M⁵³¹ represents a metal belong to Groups 8 to 11 inthe periodic table of elements, each of R⁵³³ to R⁵³¹⁰ independentlyrepresents a hydrogen atom or a substituent, each of S⁵³¹ and S⁵³²independently represents a group represented by formula (I), each of nand m represents an integer of 0 to 4, n+m is an integer of 1 to 4, andeach S⁵³¹ or S⁵³² may be the same as or different from every other S⁵³¹or S⁵³²).

In formula (5-3), M⁵³¹, R⁵³³ to R⁵³¹⁰, S⁵³¹, S⁵³², n and m have the samemeanings as M⁵¹, R⁵³ to R⁵¹⁰, S⁵¹, S⁵², n and m in formula (5), and thepreferred ranges are also the same.

The compound represented by formula (4) is preferably represented by thefollowing formula (6):

(In formula (6), M⁶¹ represents a metal belong to Groups 8 to 11 in theperiodic table of elements, each of R⁶³ to R⁶⁶ independently representsa hydrogen atom or a substituent, each of B⁶¹ to B⁶³ independentlyrepresents a nitrogen atom or C—R⁶⁷, R⁶⁷ represents a hydrogen atom or asubstituent, each R⁶⁷ may be the same as or different from every otherR⁶⁷, each of L⁶² and L⁶³ represents a carbon atom, a nitrogen atom, anoxygen atom or a phosphorus atom, E⁶¹ represents an atomic group forforming a bidentate ligand together with L⁶² and L⁶³, k represents aninteger of 1 to 3, l represents an integer of 0 to 2, k+l is 2 or 3,each of S⁶¹ and S⁶² independently represents a group represented byformula (I), each of n and m represents an integer of 0 to 4, n+m is aninteger of 1 to 4, and each S⁶¹ or S⁶² may be the same as or differentfrom every other S⁶¹ or S⁶²).

In formula (6), M⁶¹, L⁶², L⁶³, E⁶¹, S⁶¹, k and l have the same meaningsas M⁴¹, L⁴², L⁴³, E⁴¹, S⁴¹, S⁴², k and l in formula (4), and thepreferred ranges are also the same.

R⁶³ to R⁶⁶ and B⁶¹ to B⁶³ have the same meanings as R⁴³ to R⁴⁶ and B⁴¹to B⁴⁴ in formula (4), and the preferred ranges are also the same.

Each of n and m represents an integer of 0 to 4, and n+m is an integerof 1 to 4. n+m is preferably 1 or 2.

One preferred embodiment of formula (6) is represented by formula (6-1):

(In formula (6-1), M⁶¹¹ metal belong to Groups 8 to 11 in the periodictable of elements, each of R⁶¹³ to R⁶¹⁹ independently represents ahydrogen atom or a substituent, each of L⁶¹² and L⁶¹⁹ represents acarbon atom, a nitrogen atom, an oxygen atom or a phosphorus atom, E⁶¹¹represents an atomic group for forming a bidentate ligand together withL⁶¹² and L⁶¹³, k represents an integer of 1 to 3, l represents aninteger of 0 to 2, k+l is 2 or 3, each of S⁶¹¹ and S⁶¹² independentlyrepresents a group represented by formula (I), and each S⁶¹¹ or S⁶¹² maybe the same as or different from every other S⁶¹¹ or S⁶¹²).

In formula (6-1), M⁶¹¹, R⁶¹³ to R⁶¹⁹, L⁶¹², L⁶¹³, E⁶¹¹, S⁶¹¹, S⁶¹², n,m, k and l have the same meanings as M⁶¹, R⁶³ to R⁶⁶, L⁶², L⁶³, E⁶¹,S⁶¹, S⁶², n, m, k and l in formula (6), and the preferred ranges arealso the same.

Each of R⁶¹⁷ to R⁶¹⁹ independently represents a hydrogen atom or asubstituent selected from substituents including Substituent Group A.The substituent is preferably a substituted or unsubstituted alkylgroup, a cycloalkyl group, an aryl group, an amino group, an alkoxygroup, an aryloxy group, an acyl group, an alkoxycarbonyl group, anaryloxycarbonyl group, an acyloxy group, a sulfonylamino group, asulfamoyl group, a carbamoyl group, an alkylthio group, an arylthiogroup, a heterocyclic thio group, a sulfonyl group, a sulfinyl group, aureido group, a phosphoric acid amido group, a hydroxy group, a mercaptogroup, a halogen atom, a sulfo group, a carboxyl group, a nitro group, asulfino group, a heterocyclic group or a silyl group, more preferably asubstituted or unsubstituted alkyl group, a cycloalkyl group, an arylgroup, an amino group, an alkoxy group, an aryloxy group, a cyano group,a fluorine atom or a heterocyclic group, still more preferably asubstituted or unsubstituted alkyl group, a fluorine atom, a methoxygroup, an aryl group or a cyano group. In particular, the substituent ispreferably a substituted or unsubstituted alkyl group, a fluorine atomor a cyano group, and most preferably a methyl group, a trifluoromethylgroup, a fluorine atom or a cyano group.

One preferred embodiment of formula (6-1) is represented by formula(6-2):

(In formula (6-2), M⁶²¹ represents a metal belong to Groups 8 to 11 inthe periodic table of elements, each of R⁶²³ to R⁶²⁹ independentlyrepresents a hydrogen atom or a substituent, each of S⁶²¹ and S⁶²²independently represents a group represented by formula (I), each of nand m represents an integer of 0 to 4, n+m is an integer of 1 to 4, andeach S⁶²¹ or S⁶²² may be the same as or different from every other S⁶²¹or S⁶²²).

In formula (6-2), n and m have the M⁶²¹, R⁶²³ to R⁶²⁶, R⁶²⁷ to R⁶²⁹,S⁶²¹, S⁶²², n and m have the same meanings as M⁶¹¹, R⁶¹³ to R⁶¹⁶, R⁶¹⁷to R⁶¹⁹, S⁶¹¹, S⁶¹², n and m in formula (6-1), and the preferred rangesare also the same.

Each of R⁶²³ to R⁶²⁶ independently represents a hydrogen atom or asubstituent selected from substituents including Substituent Group A.The substituent is preferably a substituted or unsubstituted alkylgroup, a cycloalkyl group, an aryl group, an amino group, an alkoxygroup, an aryloxy group, an acyl group, an alkoxycarbonyl group, anaryloxycarbonyl group, an acyloxy group, a sulfonylamino group, asulfamoyl group, a carbamoyl group, an alkylthio group, an arylthiogroup, a heterocyclic thio group, a sulfonyl group, a sulfonyl group, aureido group, a phosphoric acid amido group, a hydroxy group, a mercaptogroup, a halogen atom, a sulfo group, a carboxyl group, a nitro group, asulfino group, a heterocyclic group or a silyl group, more preferably asubstituted or unsubstituted alkyl group, a cycloalkyl group, an arylgroup, an amino group, an alkoxy group, an aryloxy group, a cyano group,a fluorine atom or a heterocyclic group, still more preferably asubstituted or unsubstituted alkyl group, a fluorine atom, a methoxygroup, an aryl group or a cyano group. In particular, the substituent ispreferably a substituted or unsubstituted alkyl group, a fluorine atomor a cyano group, and most preferably a methyl group, a trifluoromethylgroup, a fluorine atom or a cyano group.

One preferred embodiment of formula (6-1) is represented by formula(6-3):

(In formula (6-3), M⁶³¹ represents a metal belong to Groups 8 to 11 inthe periodic table of elements, each of R⁶³³ to R⁶³¹² independentlyrepresents a hydrogen atom or a substituent, each of S⁶³¹ and S⁶³²independently represents a group represented by formula (I), and eachS⁶³¹ or S⁶³² may be the same as or different from every other S⁶³¹ orS⁶³²).

In formula (6-3), M⁶³¹, R⁶³³ to R⁶³⁶, R⁶³⁷ to R⁶³⁹, S⁶³¹, S⁶³², n ad mhave the same meanings as M⁶¹¹, R⁶¹³ to R⁶¹⁶, R⁶¹⁷ to R⁶¹⁹, S⁶¹¹, S⁶¹²,n and m in formula (6-1), and the preferred ranges are also the same.

Each of R⁶³¹⁰ to R⁶³¹² independently represents a hydrogen atom or asubstituent selected from substituents including Substituent Group A.The substituent is preferably a substituted or unsubstituted alkylgroup, a cycloalkyl group, an aryl group, an amino group, an alkoxygroup, an aryloxy group, an acyl group, an alkoxycarbonyl group, anaryloxycarbonyl group, an acyloxy group, a sulfonylamino group, asulfamoyl group, a carbamoyl group, an alkylthio group, an arylthiogroup, a heterocyclic thio group, a sulfonyl group, a sulfinyl group, aureido group, a phosphoric acid amido group, a hydroxy group, a mercaptogroup, a halogen atom, a sulfo group, a carboxyl group, a nitro group, asulfino group, a heterocyclic group or a say′ group, more preferably asubstituted or unsubstituted alkyl group, a cycloalkyl group, an arylgroup, an amino group, an alkoxy group, an aryloxy group, a cyano group,a fluorine atom or a heterocyclic group, still more preferably asubstituted or unsubstituted alkyl group, a fluorine atom, a methoxygroup, an aryl group or a cyano group. In particular, the substituent ispreferably a substituted or unsubstituted alkyl group, a fluorine atomor a cyano group, and most preferably a methyl group, a trifluoromethylgroup, a fluorine atom or a cyano group.

Each of R⁶³¹⁰ to R⁶³¹² is preferably a hydrogen atom, a methyl group ora tert-butyl group.

One preferred embodiment of formula (6-1) is represented by formula(6-4):

(In formula (6-4), M⁶⁴¹ represents a metal belong to Groups 8 to 11 inthe periodic table of elements, each of R⁶⁴³ to R⁶⁴⁹ independentlyrepresents a hydrogen atom or a substituent, each of S⁶⁴¹ and S⁶⁴²independently represents a group represented by formula (I), each of nand m represents an integer of 0 to 4, n+m is an integer of 1 to 4, andeach S⁶⁴¹ or S⁶⁴² may be the same as or different from every other S⁶⁴¹or S⁶⁴²).

In formula (6-4) M⁶⁴¹, R⁶⁴³ to R⁶⁴⁶, R⁶⁴⁷ to R⁶⁴⁹, S⁶⁴¹, S⁶⁴², n and mhave the same meanings as M⁶¹¹, R⁶¹³ to R⁶¹⁶, R⁶¹⁷ to R⁶¹⁹, S⁶¹¹, S⁶¹²,n and m in formula (6-1), and the preferred ranges are also the same.

The compound represented by formula (3) is preferably represented by thefollowing formula (7):

(In formula (7), M⁷¹ represents a metal belong to Groups 8 to 11 in theperiodic table of elements, each of R⁷³ to R⁷⁶ independently representsa hydrogen atom or a substituent, each of A⁷¹ and A⁷² independentlyrepresents a nitrogen atom or a carbon atom, each of D⁷¹ to D⁷³independently represents an atom selected from carbon, nitrogen, oxygen,sulfur and silicon, the bond between atoms in the 5-membered ring formedby D⁷¹ to D⁷³, A⁷¹ and A⁷² represents a single bond or a double bond,each of D⁷¹ to D⁷³ may have a substituent when these can be furthersubstituted, each of L⁷² and L⁷³ represents a carbon atom, a nitrogenatom, an oxygen atom or a phosphorus atom, E⁷¹ represents an atomicgroup for forming a bidentate ligand together with L⁷² and L⁷³, krepresents an integer of 1 to 3, l represents an integer of 0 to 2, k+lis 2 or 3, each of S⁷¹ and S⁷² independently represents a grouprepresented by formula (I), each of n and m represents an integer of 0to 4, n+m is an integer of 1 to 4, and each S⁷¹ or S⁷² may be the sameas or different from every other S⁷¹ or S⁷²).

In formula (7), M⁷¹, R⁷³ to R⁷⁶, L⁷², L⁷³, E⁷¹, S⁷¹, n, m, k and l havethe same meanings as M³¹, R³³ to R³⁶, L³², L³³, E³¹, S³¹, S³², n, m, kand l in formula (3), and the preferred ranges are also the same.

Each of A⁷¹ and A⁷² represents a nitrogen atom or a carbon atom, andthese form an aromatic heterocyclic ring or aromatic hydrocarbon ringtogether with D⁷¹ to D⁷³.

Each of D⁷¹ to D⁷³ independently represents an atom selected fromcarbon, nitrogen, oxygen, sulfur and silicon, and the bond between atomsin the 5-membered ring formed by D⁷¹ to D⁷³, A⁷¹ and A⁷² is notparticularly limited but may be any combination of a single bond and adouble bond. Each of D⁷¹ to D⁷³ is preferably a carbon atom or anitrogen atom.

In the 5-membered ring formed by D⁷¹ to D⁷³, A⁷¹ and A⁷², the number ofnitrogen atoms is preferably from 1 to 3, more preferably from 1 to 2.

Each of D⁷¹ to D⁷³ may have a substituent selected from SubstituentGroup A when these can be further substituted. The substituents maycombine with each other to form a condensed ring, and examples of thering formed include a benzene ring, a pyridine ring, a pyrazine ring, apyrimidine ring, a triazine ring, a pyridazine ring, a pyrrole ring, apyrazole ring, an imidazole ring, a triazole ring, an oxazole ring, anoxadiazole ring, a thiazole ring, a thiadiazole ring, a furan ring, athiophene ring, a selenophene ring, a silole ring, a germole ring and aphosphole ring.

The substituent is preferably a substituted or unsubstituted alkylgroup, a cycloalkyl group, an aryl group, an amino group, an alkoxygroup, an aryloxy group, an acyl group, an alkoxycarbonyl group, anaryloxycarbonyl group, an acyloxy group, a sulfonylamino group, asulfamoyl group, a carbamoyl group, an alkylthio group, an arylthiogroup, a heterocyclic thio group, a sulfonyl group, a sulfinyl group, aureido group, a phosphoric acid amido group, a hydroxy group, a mercaptogroup, a halogen atom, a sulfo group, a carboxyl group, a nitro group, asulfino group, a heterocyclic group or a silyl group, more preferably asubstituted or unsubstituted alkyl group, a cycloalkyl group, an arylgroup, an amino group, an alkoxy group, an aryloxy group, a cyano group,a fluorine atom or a heterocyclic group, still more preferably asubstituted or unsubstituted alkyl group, a fluorine atom, a methoxygroup, an aryl group or a cyano group. In particular, the substituent ispreferably a substituted or unsubstituted alkyl group, a fluorine atomor a cyano group, and most preferably a methyl group, a trifluoromethylgroup, a fluorine atom or a cyano group.

One preferred embodiment of formula (7) is represented by formula (7-1):

(In formula (7-1), M⁷¹¹ represents a metal belong to Groups 8 to 11 inthe periodic table of elements, each of R⁷¹³ to R⁷¹⁸ independentlyrepresents a hydrogen atom or a substituent, each of L⁷¹² and L⁷¹³represents a carbon atom, a nitrogen atom, an oxygen atom or aphosphorus atom, E⁷¹¹ represents an atomic group for forming a bidentateligand together with L⁷¹² and L⁷¹³, k represents an integer of 1 to 3, lrepresents an integer of 0 to 2, k+l is 2 or 3, each of S⁷¹¹ and S⁷¹²independently represents a group represented by formula (I), each of nand m represents an integer of 0 to 4, n+m is an integer of 1 to 4, andeach S′¹¹ or S⁷¹² may be the same as or different from every other S⁷¹¹or S⁷¹²).

In formula (7-1), M⁷¹¹, R⁷¹² to R⁷¹⁸, L⁷¹², L⁷¹³, E⁷¹¹, S⁷¹¹, S⁷¹², n,m, k and l have the same meanings as M⁷¹, R⁷³ to R⁷⁶, L⁷², L⁷³, E⁷¹,S⁷¹, S⁷², n, m, k and l in formula (7), and the preferred ranges arealso the same.

The compound represented by formula (2) is preferably represented by thefollowing formula (8):

(In formula (8), M⁸¹ represents a metal belong to Groups 8 to 11 in theperiodic table of elements, each of A⁸¹ to A⁸³ independently representsa nitrogen atom or a carbon atom, each of D⁸¹ to D⁸³ independentlyrepresents an atom selected from carbon, nitrogen, oxygen, sulfur andsilicon, the bond between atoms in the 5-membered ring formed by D⁸¹ toD⁸³, A⁸¹ and the N atom represents a single bond or a double bond, eachof D⁸¹ to D⁸³ when these can be further substituted may have asubstituent, Z⁸² represents an aromatic heterocyclic ring or an aromatichydrocarbon ring, each of L⁸² and L⁸³ represents a carbon atom, anitrogen atom, an oxygen atom or a phosphorus atom, E⁸¹ represents anatomic group for forming a bidentate ligand together with L⁸² and L⁸³, krepresents an integer of 1 to 3, l represents an integer of 0 to 2, k+lis 2 or 3, each of S⁸¹ and S⁸² independently represents a grouprepresented by formula (I), each of n and m represents an integer of 0to 4, n+m is an integer of 1 to 4, and each S⁸¹ or S⁸² may be the sameas or different from every other S⁸¹ or S⁸²).

In formula (8), M⁸¹, A⁸², A⁸³, Z⁸², L⁸², L⁸³, E⁸¹, S⁸¹, S⁸², n, m, k andl have the same meanings as M²¹, A²¹, A²², Z²², L²², L²³, E²¹, S²¹, S²²,n, m, 2 k and l in formula (2), and the preferred ranges are also thesame.

Each of D⁸¹ to D⁸³ independently represents an atom selected fromcarbon, nitrogen, oxygen, sulfur and silicon, and the bond between atomsin the 5-membered ring formed by D⁸¹ to D⁸³, A⁸¹ and the nitrogen atomis not particularly limited but may be any combination of a single bondand a double bond. Each of D⁸¹ to D⁸³ is preferably a carbon atom or anitrogen atom.

In the 5-membered ring formed by D⁸¹ to D⁸³, A⁸¹ and the nitrogen atom,the number of nitrogen atoms is preferably from 1 to 3, more preferablyfrom 1 to 2.

Each of D⁸¹ to D⁸³ may have a substituent selected from SubstituentGroup A when these can be further substituted. The substituents maycombine with each other to form a condensed ring, and examples of thering formed include a benzene ring, a pyridine ring, a pyrazine ring, apyrimidine ring, a triazine ring, a pyridazine ring, a pyrrole ring, apyrazole ring, an imidazole ring, a triazole ring, an oxazole ring, anoxadiazole ring, a thiazole ring, a thiadiazole ring, a furan ring, athiophene ring, a selenophene ring, a silole ring, a germole ring and aphosphole ring.

The substituent is preferably a substituted or unsubstituted alkylgroup, a cycloalkyl group, an aryl group, an amino group, an alkoxygroup, an aryloxy group, an acyl group, an alkoxycarbonyl group, anaryloxycarbonyl group, an acyloxy group, a sulfonylamino group, asulfamoyl group, a carbamoyl group, an alkylthio group, an arylthiogroup, a heterocyclic thio group, a sulfonyl group, a sulfinyl group, aureido group, a phosphoric acid amido group, a hydroxy group, a mercaptogroup, a halogen atom, a sulfo group, a carboxyl group, a nitro group, asulfino group, a heterocyclic group or a silyl group, more preferably asubstituted or unsubstituted alkyl group, a cycloalkyl group, an arylgroup, an amino group, an alkoxy group, an aryloxy group, a cyano group,a fluorine atom or a heterocyclic group, still more preferably asubstituted or unsubstituted alkyl group, a fluorine atom, a methoxygroup, an aryl group or a cyano group. In particular, the substituent ispreferably a substituted or unsubstituted alkyl group, a fluorine atomor a cyano group, and most preferably a methyl group, a trifluoromethylgroup, a fluorine atom or a cyano group.

The compound represented by formula (8) is preferably represented by thefollowing formula (9):

(In formula (9), M⁹¹ represents a metal belong to Groups 8 to 11 in theperiodic table of elements, each of R⁹³ and R⁹⁴ independently representsa hydrogen atom or a substituent, R⁹⁵ represents a hydrogen atom or asubstituent, each of B⁹¹ to B⁹⁴ independently represents a nitrogen atomor C—R⁹⁶, R⁹⁶ represents a hydrogen atom or a substituent, each R⁹⁶ maybe the same as or different from every other R⁹⁶, each of L⁹² and L⁹³represents a carbon atom, a nitrogen atom, an oxygen atom or aphosphorus atom, E⁹¹ represents an atomic group for forming a bidentateligand together with L⁹² and L⁹³, k represents an integer of 1 to 3, lrepresents an integer of 0 to 2, k+l is 2 or 3, each of S⁹¹ and S⁹²independently represents a group represented by formula (I), each of nand m represents an integer of 0 to 4, n+m is an integer of 1 to 4, andeach S⁹¹ or S⁹² may be the same as or different from every other S⁹¹ orS⁹²).

In formula (9), M⁹¹, L⁹², L⁹³, E⁹¹, S⁹¹, S⁹², n, m, k and l have thesame meanings as M⁸¹, L⁸², L⁸³, E⁸¹, S⁸¹, S⁸², n, m, k and l in formula(8), and the preferred ranges are also the same.

Each of B⁹¹ to B⁹⁴ independently represents a nitrogen atom or C—R⁹⁶,and R⁹⁶ represents a hydrogen atom or a substituent. The combination ofB⁹¹ to B⁹⁴ is not particularly limited but out of B⁹¹ to B⁹⁴, the numberof nitrogen atoms is preferably from 0 to 2, more preferably from 0 to1.

Each of R⁹³ and R⁹⁴ independently represents a hydrogen atom or asubstituent selected from substituents including Substituent Group A.The substituent is preferably a substituted or unsubstituted alkylgroup, a cycloalkyl group, an aryl group, an amino group, an alkoxygroup, an aryloxy group, an acyl group, an alkoxycarbonyl group, anaryloxycarbonyl group, an acyloxy group, a sulfonylamino group, asulfamoyl group, a carbamoyl group, an alkylthio group, an arylthiogroup, a heterocyclic thio group, a sulfonyl group, a sulfinyl group, aureido group, a phosphoric acid amido group, a hydroxy group, a mercaptogroup, a halogen atom, a sulfo group, a carboxyl group, a nitro group, asulfino group, a heterocyclic group or a silyl group, more preferably asubstituted or unsubstituted alkyl group, a cycloalkyl group, an arylgroup, an amino group, an alkoxy group, an aryloxy group, a cyano group,a fluorine atom or a heterocyclic group, still more preferably asubstituted or unsubstituted alkyl group, a fluorine atom, a methoxygroup, an aryl group or a cyano group. In particular, the substituent ispreferably a substituted or unsubstituted alkyl group, a fluorine atomor a cyano group, and most preferably a methyl group, a trifluoromethylgroup, a fluorine atom or a cyano group.

R⁹⁵ represents a hydrogen atom or a substituent selected fromsubstituents including Substituent Group A. The substituent ispreferably a substituted or unsubstituted alkyl group, a cycloalkylgroup, an aryl group, an amino group, an alkoxy group, an aryloxy group,an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, anacyloxy group, a sulfonylamino group, a sulfamoyl group, a carbamoylgroup, an alkylthio group, an arylthio group, a heterocyclic thio group,a sulfonyl group, a sulfinyl group, a ureido group, a phosphoric acidamido group, a hydroxy group, a mercapto group, a halogen atom, a sulfogroup, a carboxyl group, a nitro group, a sulfino group, a heterocyclicgroup or a silyl group, more preferably a substituted or unsubstitutedalkyl group, a cycloalkyl group, an aryl group, an alkoxy group, anaryloxy group, a cyano group, a fluorine atom or a heterocyclic group,still more preferably a substituted or unsubstituted alkyl group, acycloalkyl group, a trifluoromethyl group or an aryl group.

As for the substituent represented by R⁹⁶, those described above asSubstituent Group A can be applied.

Each R⁹⁶ may be the same as or different from every other R⁹⁶. R⁹⁶ mayfurther have a substituent, and those described above as SubstituentGroup A can be applied to the substituent. Also, R⁹⁶'s may combine witheach other to form a condensed ring, and examples of the ring formedinclude a benzene ring, a pyridine ring, a pyrazine ring, a pyrimidinering, a triazine ring, a pyridazine ring, a pyrrole ring, a pyrazolering, an imidazole ring, a triazole ring, an oxazole ring, an oxadiazolering, a thiazole ring, a thiadiazole ring, a furan ring, a thiophenering, a selenophene ring, a silole ring, a germole ring and a phospholering.

R⁹⁶ is preferably a substituted or unsubstituted alkyl group, acycloalkyl group, an aryl group, an amino group, an alkoxy group, anaryloxy group, an acyl group, an alkoxycarbonyl group, anaryloxycarbonyl group, an acyloxy group, a sulfonylamino group, asulfamoyl group, a carbamoyl group, an alkylthio group, an arylthiogroup, a heterocyclic thio group, a sulfonyl group, a sulfinyl group, aureido group, a phosphoric acid amido group, a hydroxy group, a mercaptogroup, a halogen atom, a sulfo group, a carboxyl group, a nitro group, asulfino group, a heterocyclic group or a silyl group, more preferably asubstituted or unsubstituted alkyl group, a cycloalkyl group, an arylgroup, an amino group, an alkoxy group, an aryloxy group, a cyano group,a fluorine atom or a heterocyclic group, still more preferably asubstituted or unsubstituted alkyl group, a fluorine atom, a methoxygroup, an aryl group or a cyano group. In particular, the substituent ispreferably a substituted or unsubstituted alkyl group, a fluorine atomor a cyano group, and most preferably a methyl group, a trifluoromethylgroup, a fluorine atom or a cyano group.

The compound represented by formula (9) is preferably represented by thefollowing formula (10):

(In formula (10), M¹⁰¹ represents a metal belong to Groups 8 to 11 inthe periodic table of elements, each of R¹⁰³ to R¹⁰⁸ independentlyrepresents a hydrogen atom or a substituent, R¹⁰⁹ represents a hydrogenatom or a substituent, each of L¹⁰² and L¹⁰³ represents a carbon atom, anitrogen atom, an oxygen atom or a phosphorus atom, E¹⁰¹ represents anatomic group for forming a bidentate ligand together with L¹⁰² and L¹⁰³,k represents an integer of 1 to 3, l represents an integer of 0 to 2,k+l is 2 or 3, each of S¹⁰¹ and S¹⁰² independently represents a grouprepresented by formula (I), each of n and m represents an integer of 0to 4, n+m is an integer of 1 to 4, and each S¹⁰¹ or S¹⁰² may be the sameas or different from every other S¹⁰¹ or S¹⁰²).

In formula (10), M¹⁰¹, L¹⁰², L¹⁰³, E¹⁰¹, S¹⁰¹, S¹⁰², k and l have thesame meanings as M⁹¹, L⁹², L⁹³, E⁹¹, S⁹¹, S⁹², k and l in formula (9),and the preferred ranges are also the same.

R¹⁰³ to R¹⁰⁸ have the same meanings as R⁹³ and R⁹⁴, and the preferredranges are also the same.

R¹⁰⁹ has the same meaning as R⁹⁵, and the preferred range is also thesame.

Each of n and m represents an integer of 0 to 4, and n+m is an integerof 1 to 4. n+m is preferably 1 or 2.

The compound represented by formula (9) is preferably represented by thefollowing formula (11):

(In formula (11), M¹¹¹ represents a metal belong to Groups 8 to 11 inthe periodic table of elements, each of R¹¹³ and R¹¹⁴ independentlyrepresents a hydrogen atom or a substituent, R¹¹⁵ represents a hydrogenatom or a substituent, each of B¹¹¹ to B¹¹³ independently represents anitrogen atom or C—R¹¹⁶, represents a hydrogen atom or a substituent,each R¹¹⁶ may be the same as or different from every other R¹¹⁶, each ofL¹¹² and L¹¹³ represents a carbon atom, a nitrogen atom, an oxygen atomor a phosphorus atom, E¹¹¹ represents an atomic group for forming abidentate ligand together with L¹¹² and L¹¹³, k represents an integer of1 to 3, l represents an integer of 0 to 2, k+l is 2 or 3, each of S¹¹¹and S¹¹² independently represents a group represented by formula (I),each of n and m represents an integer of 0 to 4, n+m is an integer of 1to 4, and each S¹¹¹ or S¹¹² may be the same as or different from everyother S¹¹¹ or S¹¹²).

In formula (11), S¹¹¹, S¹¹², k and 1 have the same meanings as M⁹¹, S⁹¹,S⁹², k and l in formula (9), and the preferred ranges are also the same.

R¹¹³ and R¹¹⁴ have the same meanings as R⁹³ and R⁹⁴, and the preferredranges are also the same.

R¹¹⁶ has the same meaning as R⁹⁵, and the preferred range is also thesame.

B¹¹¹ to B¹¹⁴ have the same meanings as B⁹¹ to B⁹⁴, and the preferredranges are also the same.

Each of n and m represents an integer of 0 to 4, and n+m is an integerof 1 to 4. n+m is preferably 1 or 2.

One preferred embodiment of formula (11) is represented by formula(11-1):

(In formula (11-1), represents a metal belong to Groups 8 to 11 in theperiodic table of elements, each of R¹¹¹³ and R¹¹¹⁴ independentlyrepresents a hydrogen atom or a substituent, R¹¹¹⁵ represents a hydrogenatom or a substituent, each of R¹¹¹⁶ to R¹¹¹⁸ independently represents ahydrogen atom or a substituent, each of L¹¹¹² and L¹¹¹³ represents acarbon atom, a nitrogen atom, an oxygen atom or a phosphorus atom, E¹¹¹¹represents an atomic group for forming a bidentate ligand together withL¹¹¹² and L¹¹¹³, k represents an integer of 1 to 3, l represents aninteger of 0 to 2, k+l is 2 or 3, each of S¹¹¹¹ and S¹¹¹² independentlyrepresents a group represented by formula (I), each of n or S¹¹¹² and mrepresents an integer of 0 to 4, n+m is an integer of 1 to 4, and each Smay be the same as or different from every other S¹¹¹¹ or S¹¹¹²).

In formula (11-1), M¹¹¹¹, R¹¹¹³, R¹¹¹⁴, R¹¹¹⁵, L¹¹¹², L¹¹¹³, E¹¹¹¹,S¹¹¹¹, S¹¹¹², n, m, k and l have the same meanings as M⁹¹, R⁹³, R⁹⁴,R⁹⁵, L⁹², L⁹³, E⁹¹, S⁹¹, S⁹², n, m, k and l in formula (9), and thepreferred ranges are also the same.

Each of R¹¹¹⁶ to R¹¹¹⁸ independently represents a hydrogen atom or asubstituent selected from substituents including Substituent Group A.The substituent is preferably a substituted or unsubstituted alkylgroup, a cycloalkyl group, an aryl group, an amino group, an alkoxygroup, an aryloxy group, an acyl group, an alkoxycarbonyl group, anaryloxycarbonyl group, an acyloxy group, a sulfonylamino group, asulfamoyl group, a carbamoyl group, an alkylthio group, an arylthiogroup, a heterocyclic thio group, a sulfonyl group, a sulfinyl group, aureido group, a phosphoric acid amido group, a hydroxy group, a mercaptogroup, a halogen atom, a sulfo group, a carboxyl group, a nitro group, asulfino group, a heterocyclic group or a silyl group, more preferably asubstituted or unsubstituted alkyl group, a cycloalkyl group, an arylgroup, an amino group, an alkoxy group, an aryloxy group, a cyano group,a fluorine atom or a heterocyclic group, still more preferably asubstituted or unsubstituted alkyl group, a fluorine atom, a methoxygroup, an aryl group or a cyano group. In particular, the substituent ispreferably a substituted or unsubstituted alkyl group, a fluorine atomor a cyano group, and most preferably a methyl group, a trifluoromethylgroup, a fluorine atom or a cyano group.

One preferred embodiment of formula (11-1) is represented by formula(11-2):

(In formula (11-2), M¹¹²¹ represents a metal belong to Groups 8 to 11 inthe periodic table of elements, each of R¹¹²³ and R¹¹²⁴ independentlyrepresents a hydrogen atom or a substituent, R¹¹²⁵ represents a hydrogenatom or a substituent, each of R¹¹²⁶ to R¹¹²⁸ and R¹¹²⁹ to R¹¹²¹²independently represents a hydrogen atom or a substituent, each of S¹¹²¹and S¹¹²² independently represents a group represented by formula (I),each of n and m represents an integer of 0 to 4, n+m is an integer of 1to 4, and each S¹¹²¹ or S¹¹²² may be the same as or different from everyother S¹¹²¹ or S¹¹²²).

In formula (11-2) M¹¹²¹, R¹¹²³, R¹¹²⁴, R¹¹²⁵, R¹¹²⁶ to R¹¹²⁸, S¹¹²¹,S¹¹²², n and m, have the same meanings as M¹¹¹¹, M¹¹¹, R¹¹¹⁴, R¹¹¹⁵,R¹¹¹⁶, to R¹¹¹⁸, S¹¹¹¹, S¹¹¹², n and m in formula (11-1), and thepreferred ranges are also the same.

Each of R¹¹²⁹ to R¹¹²¹² independently represents a hydrogen atom or asubstituent selected from substituents including Substituent Group A.The substituent is preferably a substituted or unsubstituted alkylgroup, a cycloalkyl group, an aryl group, an amino group, an alkoxygroup, an aryloxy group, an acyl group, an alkoxycarbonyl group, anaryloxycarbonyl group, an acyloxy group, a sulfonylamino group, asulfamoyl group, a carbamoyl group, an alkylthio group, an arylthiogroup, a heterocyclic thio group, a sulfonyl group, a sulfinyl group, aureido group, a phosphoric acid amido group, a hydroxy group, a mercaptogroup, a halogen atom, a sulfo group, a carboxyl group, a nitro group, asulfino group, a heterocyclic group or a silyl group, more preferably asubstituted or unsubstituted alkyl group, a cycloalkyl group, an arylgroup, an amino group, an alkoxy group, an aryloxy group, a cyano group,a fluorine atom or a heterocyclic group, still more preferably asubstituted or unsubstituted alkyl group, a fluorine atom, a methoxygroup, an aryl group or a cyano group. In particular, the substituent ispreferably a substituted or unsubstituted alkyl group, a fluorine atomor a cyano group, and most preferably a methyl group, a trifluoromethylgroup, a fluorine atom or a cyano group.

Each of R¹¹²⁹ to R¹¹²¹² is preferably a hydrogen atom.

One preferred embodiment of formula (11-1) is represented by formula(11-3):

(In formula (11-3), M¹¹³¹ represents a metal belong to Groups 8 to 11 inthe periodic table of elements, each of R¹¹³³ and R¹¹³⁴ independentlyrepresents a hydrogen atom or a substituent, R¹¹³⁵ represents a hydrogenatom or a substituent, each of R¹¹³⁶ to R¹¹³⁸ and R¹¹³⁹ to R¹¹³¹¹independently represents a hydrogen atom or a substituent, each of S¹¹³¹and S¹³² independently represents a group represented by formula (I),each of n and m represents an integer of 0 to 4, and n+m is an integerof 1 to 4).

In formula (11-3), M¹¹³¹, R¹¹³³, R¹¹³⁴, R¹¹³⁵, R¹¹³⁶ to R¹¹³⁸, S¹¹³¹,S¹¹³², n and m have the same meanings as M¹¹¹¹, R¹¹¹³, R¹¹¹⁴, R¹¹¹⁵,R¹¹¹⁶ to R¹¹¹⁸, S¹¹¹¹, S¹¹², n and m in formula (11-1), and thepreferred ranges are also the same.

Each of R¹¹³⁹ to R¹¹³¹¹ independently represents a hydrogen atom or asubstituent selected from substituents including Substituent Group A.The substituent is preferably a substituted or unsubstituted alkylgroup, a cycloalkyl group, an aryl group, an amino group, an alkoxygroup, an aryloxy group, an acyl group, an alkoxycarbonyl group, anaryloxycarbonyl group, an acyloxy group, a sulfonylamino group, asulfamoyl group, a carbamoyl group, an alkylthio group, an arylthiogroup, a heterocyclic thio group, a sulfonyl group, a sulfinyl group, aureido group, a phosphoric acid amido group, a hydroxy group, a mercaptogroup, a halogen atom, a sulfo group, a carboxyl group, a nitro group, asulfino group, a heterocyclic group or a silyl group, more preferably asubstituted or unsubstituted alkyl group, a cycloalkyl group, an arylgroup, an amino group, an alkoxy group, an aryloxy group, a cyano group,a fluorine atom or a heterocyclic group, still more preferably asubstituted or unsubstituted alkyl group, a fluorine atom, a methoxygroup, an aryl group or a cyano group. In particular, the substituent ispreferably a substituted or unsubstituted alkyl group, a fluorine atomor a cyano group, and most preferably a methyl group, a trifluoromethylgroup, a fluorine atom or a cyano group.

Each of R¹¹³⁹ to R¹¹³¹¹ is preferably a hydrogen atom or a methyl group.

One preferred embodiment of formula (11-1) is represented by formula(11-4):

(In formula (11-4), M¹¹⁴¹ represents a metal belong to Groups 8 to 11 inthe periodic table of elements, each of R¹¹⁴³ and R¹¹⁴⁴ independentlyrepresents a hydrogen atom or a substituent, R¹¹⁴⁵ represents a hydrogenatom or a substituent, each of R¹¹⁴⁶ to R¹¹⁴⁸ independently represents ahydrogen atom or a substituent, each of S¹⁴¹¹ and S¹¹⁴² independentlyrepresents a group represented by formula (I), each of n and mrepresents an integer of 0 to 4, n+m is an integer of 1 to 4, and eachS¹¹⁴¹ or S¹¹⁴² may be the same as or different from every other S¹¹⁴¹ orS¹¹⁴²).

In formula (11-4), M¹¹⁴¹, R¹¹⁴³, R¹¹⁴⁴, R¹¹⁴⁵, R¹¹⁴⁶ to R¹¹⁴⁸, S¹¹⁴¹,S¹¹⁴², n and m have the same meanings as M¹¹¹¹, R¹¹³, R¹¹⁴, R¹¹¹⁵, R¹¹¹⁶to R¹¹¹⁸, S¹¹¹¹, S¹¹¹², n and m in formula (11-1), and the preferredranges are also the same.

The compound represented by formula (8) is preferably represented by thefollowing formula (12):

(In formula (12), M¹²¹ represents a metal belong to Groups 8 to 11 inthe periodic table of elements, each of R¹²³ to R¹²⁵ independentlyrepresents a hydrogen atom or a substituent, each of B¹²¹ to B¹²⁴independently represents a nitrogen atom or C—R¹²⁶, R¹²⁶ represents ahydrogen atom or a substituent, each R¹²⁶ may be the same as ordifferent from every other R¹²⁶, each of L¹²² and L¹²³ represents acarbon atom, a nitrogen atom, an oxygen atom or a phosphorus atom, E¹²¹represents an atomic group for forming a bidentate ligand together withL¹²² and L¹²³, k, represents an integer of 1 to 3, l represents aninteger of 0 to 2, k+l is 2 or 3, each of S¹²¹ and S¹²² independentlyrepresents a group represented by formula (I), each of n and mrepresents an integer of 0 to 4, n+m is an integer of 1 to 4, and eachS¹²¹ or S¹²² may be the same as or different from every other S¹²¹ orS¹²²).

In formula (12), M¹²¹, L¹²², L¹²³, E¹²¹, S¹²¹, S¹²², n, m, k and l havethe same meanings as M⁸¹, L⁸², L⁸³, B⁸¹, E⁸¹, S⁸¹, S⁸², n, m, k and l informula (8), and the preferred ranges are also the same.

Each of R¹²³ to R¹²⁵ independently represents a hydrogen atom or asubstituent selected from substituents including Substituent Group A.The substituent is preferably a substituted or unsubstituted alkylgroup, a cycloalkyl group, an aryl group, an amino group, an alkoxygroup, an aryloxy group, an acyl group, an alkoxycarbonyl group, anaryloxycarbonyl group, an acyloxy group, a sulfonylamino group, asulfamoyl group, a carbamoyl group, an alkylthio group, an arylthiogroup, a heterocyclic thio group, a sulfonyl group, a sulfinyl group, aureido group, a phosphoric acid amido group, a hydroxy group, a mercaptogroup, a halogen atom, a sulfo group, a carboxyl group, a nitro group, asulfino group, a heterocyclic group or a silyl group, more preferably asubstituted or unsubstituted alkyl group, a cycloalkyl group, an arylgroup, an amino group, an alkoxy group, an aryloxy group, a cyano group,a fluorine atom or a heterocyclic group, still more preferably asubstituted or unsubstituted alkyl group, a fluorine atom, a methoxygroup, an aryl group or a cyano group. In particular, the substituent ispreferably a substituted or unsubstituted alkyl group, a fluorine atomor a cyano group, and most preferably a methyl group, a trifluoromethylgroup, a fluorine atom or a cyano group.

Each of B¹²¹ to B¹²⁴ independently represents a nitrogen atom or C—R¹²⁶,and R¹²⁶ represents a hydrogen atom or a substituent. The combination ofB¹²¹ to B¹²⁴ is not particularly limited but out of B¹²¹ to B¹²⁴, thenumber of nitrogen atoms is preferably from 0 to 2, more preferably from0 to 1.

As for the substituent represented by R¹²⁶, those described above asSubstituent Group A can be applied.

Each R¹²⁶ may be the same as or different from every other R¹²⁶. R¹²⁶may further have a substituent, and those described above as SubstituentGroup A can be applied to the substituent. Also, R¹²⁶'s may combine witheach other to form a condensed ring, and examples of the ring formedinclude a benzene ring, a pyridine ring, a pyrazine ring, a pyrimidinering, a triazine ring, a pyridazine ring, a pyrrole ring, a pyrazolering, an imidazole ring, a triazole ring, an oxazole ring, an oxadiazolering, a thiazole ring, a thiadiazole ring, a furan ring, a thiophenering, a selenophene ring, a silole ring, a germole ring and a phospholering.

R¹²⁶ is preferably a substituted or unsubstituted alkyl group, acycloalkyl group, an aryl group, an amino group, an alkoxy group, anaryloxy group, an acyl group, an alkoxycarbonyl group, anaryloxycarbonyl group, an acyloxy group, a sulfonylamino group, asulfamoyl group, a carbamoyl group, an alkylthio group, an arylthiogroup, a heterocyclic thio group, a sulfonyl group, a sulfinyl group, aureido group, a phosphoric acid amido group, a hydroxy group, a mercaptogroup, a halogen atom, a sulfo group, a carboxyl group, a nitro group, asulfino group, a heterocyclic group or a silyl group, more preferably asubstituted or unsubstituted alkyl group, a cycloalkyl group, an arylgroup, an amino group, an alkoxy group, an aryloxy group, a cyano group,a fluorine atom or a heterocyclic group, still more preferably asubstituted or unsubstituted alkyl group, a fluorine atom, a methoxygroup, an aryl group or a cyano group. In particular, the substituent ispreferably a substituted or unsubstituted alkyl group, a fluorine atomor a cyano group, and most preferably a methyl group, a trifluoromethylgroup, a fluorine atom or a cyano group.

One preferred embodiment of formula (12) is represented by formula(12-1):

(In formula (12-1), M¹²¹¹ represents a metal belong to Groups 8 to 11 inthe periodic table of elements, each of R¹²¹³ to R¹²¹⁵ independentlyrepresents a hydrogen atom or a substituent, each of B¹²¹¹ to B¹²¹³independently represents a nitrogen atom or C—R¹²¹⁶, R¹²¹⁶ represents ahydrogen atom or a substituent, each R¹²¹⁶ may be the same as ordifferent from every other R¹²¹⁶, each of L¹²¹² and L¹²¹³ represents acarbon atom, a nitrogen atom, an oxygen atom or a phosphorus atom, E¹²¹¹represents an atomic group for forming a bidentate ligand together withL¹²¹² and L¹²¹³, k represents an integer of 1 to 3, l represents aninteger of 0 to 2, k+l is 2 or 3, each of S¹²¹¹ and S¹²¹² independentlyrepresents a group represented by formula (I), each of n and mrepresents an integer of 0 to 4, n+m is an integer of 1 to 4, and eachS¹²¹¹ or S¹²¹² may be the same as or different from every other S¹²¹¹ orS¹²¹²).

In formula (12-1), M¹²¹¹, R¹²¹³ to R¹²¹⁵, B¹²¹¹ to B¹²¹³, L¹²¹², L¹²¹³,E¹²¹¹, S¹²¹¹, S¹²¹², n, m, k and l have the same meanings as M¹²¹, R¹²³to R¹²⁵, B¹²¹, to B¹²⁴, L¹²², L¹²³, S¹²¹, S¹²¹, S¹²², n, m, k and l informula (12), and the preferred ranges are also the same.

Formula (12) is preferably represented by formula (12-2).

(In formula (12-2), M¹²²¹ represents a metal belong to Groups 8 to 11 inthe periodic table of elements, each of R¹²²³ to R¹²²⁹ independentlyrepresents a hydrogen atom or a substituent, each of L¹²²² and L¹²²³represents a carbon atom, a nitrogen atom, an oxygen atom or aphosphorus atom, E¹²²¹ represents an atomic group for forming abidentate ligand together with L¹²²² and L¹²²³, k represents an integerof 1 to 3, l represents an integer of 0 to 2, k+l is 2 or 3, each ofS¹²²¹ and S¹²²² independently represents a group represented by formula(I), each of n and m represents an integer of 0 to 4, n+m is an integerof 1 to 4, and each S¹²²¹ or S¹²²² may be the same as or different fromevery other S¹²²¹ or S¹²²²).

In formula (12-2), M¹²²¹, R¹²²³ to R¹²²⁵, L¹²²², L¹²²³, E¹²²¹, S¹²²¹,S¹²²², n, m, k and l have the same meanings as M¹²¹, R¹²³ to R¹²⁵, L¹²²,L¹²³, E¹²¹, S¹²¹, S¹²², n, m, k and l in formula (12), and the preferredranges are also the same.

Each of R¹²²⁶ to R¹²²⁹ independently represents a hydrogen atom or mayhave a substituent selected from substituents including SubstituentGroup A, and the preferred ranges are the same as that of R¹²⁶ informula (12).

The compound represented by formula (1) is preferably represented by thefollowing formula (13):

(In formula (13), each of A¹³¹ and A¹³² represents a nitrogen atom or acarbon atom, each of Y¹³¹ and Y¹³² represents a linking group or asingle bond, each of L¹³¹ and L¹³² represents a partial structure havingan atom bonded to Pt, each of Z¹³¹ and Z¹³² represents an aromaticnitrogen-containing heterocyclic ring, each of X¹³¹ and X¹³² representsan oxygen atom, a sulfur atom, a substituted or unsubstituted nitrogenatom or a single bond, E¹³¹ represents a divalent linking group, each ofS¹³¹ and S¹³² independently represents a group represented by formula(I), each of n and m represents an integer of 0 to 4, n+m is an integerof 1 to 4, and each S¹³¹ or S¹³² may be the same as or different fromevery other S¹³¹ or S¹³²).

In formula (13), A¹³¹, to A¹³⁶, Z¹³¹ to Z¹³⁴, S¹³¹ to S¹³⁴, L¹³¹, L¹³²,X¹³¹, X¹³², Y¹³¹, Y¹³², n, m, k and l have the same meanings as A¹¹ toA¹³, Z¹¹, Z¹², S¹¹, S¹², L¹¹, X¹¹, Y¹¹, n, m, k and l in formula (1),and the preferred ranges are also the same.

E¹³¹ represents a divalent linking group. The linking group is notparticularly limited but is preferably a divalent linking group composedof a single bond, a carbon atom, a nitrogen atom, an oxygen atom, asulfur atom, a silicon atom or a germanium atom, more preferably a groupselected from Linking Group A.

E¹³¹ is preferably a substituent selected from Linking Group A, andamong these, —C(R¹)(R²)—, —C(R³)(R⁴)C(R⁵)(R⁶)—, —Si(R⁷)(R⁸)—, —N(R⁹)—,—O—, —S—, —SO—, —SO₂— and —CO— are preferred, —C(R¹)(R²)—,—C(R³)(R⁴)C(R⁵)(R⁶)—, —Si(R⁷)(R⁸)—, —O— and —S— are more preferred,—C(R¹)(R²)— and —C(R³)(R⁴)C(R⁵)(R⁶)— are still more preferred.

In —C(R¹)(R²)—, each of R¹ and R² is preferably a hydrogen atom or asubstituent selected from Substituent Group B.

In —C(R³)(R⁴)C(R⁵)(R⁶)—, each of R³, R⁴, R⁵ and R⁶ is preferably ahydrogen atom or a substituent selected from Substituent Group B.

In —Si(R⁷)(R⁸)—, each of R⁷ and R⁸ is preferably a hydrogen atom or asubstituent selected from Substituent Group B.

In)—Ge(R¹⁰)(R¹¹)—, each of R¹⁰ and R¹¹ is preferably a hydrogen atom ora substituent selected from Substituent Group B.

In —N(R⁹)—, R⁹ is preferably a hydrogen atom, an alkyl group, acycloalkyl group or an aryl group, more preferably an alkyl group or anaryl group, still more preferably an aryl group.

In —P(R¹²)—, R¹² has the same meaning as the preferred range of R⁹.

In formula (13), examples of the aromatic nitrogen-containingheterocyclic ring represented by Z¹³¹ and Z¹³² include a pyridine ring,a pyridazine ring, a pyrimidine ring, a pyrazine ring, a triazine ring,a benzimidazole ring, an oxadiazole ring, a triazole ring, an imidazolering, a pyrazole ring, a thiazole ring, an oxazole ring, a benzimidazolering, a benzothiazole ring, a benzoxazole ring, an isoquinoline ring, aquinoxaline ring, a quinazoline ring, a phthalazine ring, a carbolinering, and a ring where a carbon atom of a hydrocarbon ring constitutinga carboline ring is further substituted with a nitrogen atom.

Each of Z¹³¹ and Z¹³² is preferably a pyridine ring, a pyrimidine ring,a pyrazine ring, a benzimidazole ring, an oxadiazole ring, a triazolering, an imidazole ring, a pyrazole ring, a thiazole ring, an oxazolering, a benzimidazole ring, a benzothiazole ring, a benzoxazole ring, anisoquinoline ring or a quinoxaline ring, more preferably a pyridinering, a pyrimidine ring, a pyrazine ring, an imidazole ring, a pyrazolering, an isoquinoline ring or a quinoxaline ring, still more preferablyan isoquinoline ring, a benzoxazole ring, a pyridine ring, an imidazolering or a pyrazole ring.

The aromatic nitrogen-containing heterocyclic ring may have asubstituent, and those described as Substituent Group A can be appliedto the substituent.

The substituent is preferably a substituted or unsubstituted alkylgroup, a cycloalkyl group, an aryl group, an amino group, an alkoxygroup, an aryloxy group, an acyl group, an alkoxycarbonyl group, anaryloxycarbonyl group, an acyloxy group, a sulfonylamino group, asulfamoyl group, a carbamoyl group, an alkylthio group, an arylthiogroup, a heterocyclic thio group, a sulfonyl group, a sulfinyl group, aureido group, a phosphoric acid amido group, a hydroxy group, a mercaptogroup, a halogen atom, a sulfo group, a carboxyl group, a nitro group, asulfino group, a heterocyclic group or a silyl group, more preferably asubstituted or unsubstituted alkyl group, a cycloalkyl group, an arylgroup, an amino group, an alkoxy group, an aryloxy group, a cyano group,a fluorine atom or a heterocyclic group, stil, still more preferably asubstituted or unsubstituted alkyl group, a fluorine atom, a methoxygroup, an aryl group or a cyano group. In particular, the substituent ispreferably a substituted or unsubstituted alkyl group, a fluorine atomor a cyano group, and most preferably a methyl group, a trifluoromethylgroup, a fluorine atom or a cyano group.

The compound represented by formula (13) is preferably represented bythe following formula (14):

(In formula (14), each of A¹⁴¹ to A¹⁴⁶ independently represents anitrogen atom or a carbon atom, each of Z¹⁴¹ and Z¹⁴² independentlyrepresents an aromatic nitrogen-containing heterocyclic ring, each ofZ¹⁴³ and Z¹⁴⁴ independently represents an aromatic heterocyclic ring oran aromatic hydrocarbon ring, E¹⁴¹ represents a divalent linking group,each of S¹⁴¹ to S¹⁴⁴ independently represents a group represented byformula (I), each of n, m, k and l represents an integer of 0 to 4,n+m+k+l is an integer of 1 to 4, and each S¹⁴¹, S¹⁴², S¹⁴³ or S¹⁴⁴,S¹⁴², may be the same as or different from every other S¹⁴¹, S¹⁴², S¹⁴³or S¹⁴⁴).

In formula (14), A¹⁴¹, to A¹⁴⁶, Z¹⁴¹ to Z¹⁴⁴, S¹⁴¹ to S¹⁴⁴, E¹⁴¹, n, m,k and l have the same meanings as A¹³¹ to A¹³³, Z¹³¹, Z¹³², S¹³¹, S¹³²,E¹³¹, n, m, k and l in formula (13), and the preferred ranges are alsothe same.

Each of n and m represents an integer of 0 to 4, and n+m is an integerof 1 to 4. n+m is preferably 1 or 2.

The compound represented by formula (14) is preferably represented bythe following formula (15):

(In formula (15), each of A¹⁵¹ to A¹⁵⁴ independently represents anitrogen atom or a carbon atom, each of R¹⁵³ to R¹⁵⁸ independentlyrepresents a hydrogen atom or a substituent, each of Z¹⁵¹ and Z¹⁵²independently represents an aromatic heterocyclic ring or an aromatichydrocarbon ring, E¹⁵¹ represents a divalent linking group, each of S¹⁵¹to S¹⁵⁴ independently represents a group represented by formula (I),each of n, m, k and l represents an integer of 0 to 4, n+m+k+l is aninteger of 1 to 4, and each S¹⁵¹, S¹⁵², S¹⁵³ or S¹⁵⁴ may be the same asor different from every other S¹⁵¹, S¹⁵², S¹⁵³ or S¹⁵⁴).

In formula (15), A¹⁵¹, A¹⁵², A¹⁵³, A¹⁵³, Z¹⁵¹, Z¹⁵², E¹⁵¹, S¹⁵¹ to S¹⁵⁴,n, m, k and l have the same meanings as A¹⁴², A¹⁴³, A¹⁴⁵, A¹⁴⁶, Z¹⁴³,Z¹⁴⁴, E¹⁴¹, S¹⁴¹ to S¹⁴⁴, n, m, k and l in formula (14), and thepreferred ranges are also the same.

Each of R¹⁵³ to R¹⁵⁸ independently represents a hydrogen atom or mayhave a substituent selected from substituents including SubstituentGroup A. The substituent is preferably a substituted or unsubstitutedalkyl group, a cycloalkyl group, an aryl group, an amino group, analkoxy group, an aryloxy group, an acyl group, an alkoxycarbonyl group,an aryloxycarbonyl group, an acyloxy group, a sulfonylamino group, asulfamoyl group, a carbamoyl group, an alkylthio group, an arylthiogroup, a heterocyclic thio group, a sulfonyl group, a sulfinyl group, aureido group, a phosphoric acid amido group, a hydroxy group, a mercaptogroup, a halogen atom, a sulfo group, a carboxyl group, a nitro group, asulfino group, a heterocyclic group or a silyl group, more preferably asubstituted or unsubstituted alkyl group, a cycloalkyl group, an arylgroup, an amino group, an alkoxy group, an aryloxy group, a cyano group,a fluorine atom or a heterocyclic group, still more preferably asubstituted or unsubstituted alkyl group, a fluorine atom, a methoxygroup, an aryl group or a cyano group. In particular, the substituent ispreferably a substituted or unsubstituted alkyl group, a fluorine atomor a cyano group, and most preferably a methyl group, a trifluoromethylgroup, a fluorine atom or a cyano group.

The compound represented by formula (15) is preferably represented bythe following formula (16):

(In formula (16), each of R¹⁶³ to R¹⁶⁸ independently represents ahydrogen atom or a substituent, each of B¹⁶¹ to B¹⁶⁸ independentlyrepresents a nitrogen atom or C—R¹⁶⁹, R¹⁶⁹ represents a hydrogen atom ora substituent, each R¹⁶⁹ may be the same as or different from everyother R¹⁶⁹, E¹⁶¹ represents a divalent linking group, each of S¹⁶¹ toS¹⁶⁴ independently represents a group represented by formula (I), eachof n, m, k and l represents an integer of 0 to 4, n+m+k+l is an integerof 1 to 4, and each S or S¹⁶⁴ may be the same as or different from everyother S¹⁶¹, S¹⁶², S¹⁶³ or S¹⁶⁴).

In formula (16), R¹⁶³ to R¹⁶⁸, E¹⁶¹, S¹⁶¹ to S¹⁶⁴, n, m, k and l havethe same meanings as R¹⁵³ to R¹⁵⁸, E¹⁵¹, S¹⁵¹ to S¹⁵⁴, n, m, k and l informula (15), and the preferred ranges are also the same.

Each of B¹⁶¹ to B¹⁶⁸ independently represents a nitrogen atom or C—R¹⁶⁹,and R¹⁶⁹ represents a hydrogen atom or a substituent. The combination ofB¹⁶¹ to B¹⁶⁴ is not particularly limited but out of B¹⁶¹ to B¹⁶⁴, thenumber of nitrogen atoms is preferably from 0 to 2, more preferably from0 to 1, and out of B¹⁶⁵ to B¹⁶⁸, the number of nitrogen atoms ispreferably from 0 to 2, more preferably from 0 to 1.

As for the substituent represented by R¹⁶⁹, those described asSubstituent Group A can be applied.

Each R¹⁶⁹ may be the same as or different from every other R¹⁶⁹. R¹⁶⁹may further have a substituent, and those described above as SubstituentGroup A can be applied to the substituent. Also, R¹⁶⁹'s may combine witheach other to form a condensed ring, and examples of the ring formedinclude a benzene ring, a pyridine ring, a pyrazine ring, a pyrimidinering, a triazine ring, a pyridazine ring, a pyrrole ring, a pyrazolering, an imidazole ring, a triazole ring, an oxazole ring, an oxadiazolering, a thiazole ring, a thiadiazole ring, a furan ring, a thiophenering, a selenophene ring, a silole ring, a germole ring and a phospholering.

R¹⁶⁹ is preferably a substituted or unsubstituted alkyl group, acycloalkyl group, an aryl group, an amino group, an alkoxy group, anaryloxy group, an acyl group, an alkoxycarbonyl group, anaryloxycarbonyl group, an acyloxy group, a sulfonylamino group, asulfamoyl group, a carbamoyl group, an alkylthio group, an arylthiogroup, a heterocyclic thio group, a sulfonyl group, a sulfinyl group, aureido group, a phosphoric acid amido group, a hydroxy group, a mercaptogroup, a halogen atom, a sulfo group, a carboxyl group, a nitro group, asulfino group, a heterocyclic group or a silyl group, more preferably asubstituted or unsubstituted alkyl group, a cycloalkyl group, an arylgroup, an amino group, an alkoxy group, an aryloxy group, a cyano group,a fluorine atom or a heterocyclic group, still more preferably asubstituted or unsubstituted alkyl group, a fluorine atom, a methoxygroup, an aryl group or a cyano group. In particular, the substituent ispreferably a substituted or unsubstituted alkyl group, a fluorine atomor a cyano group, and most preferably a methyl group, a trifluoromethylgroup, a fluorine atom or a cyano group.

The compound represented by formula (15) is preferably represented bythe following formula (17):

(In formula (17), each of R¹⁷³ to R¹⁷⁸ independently represents ahydrogen atom or a substituent, each of A¹⁷¹ to A¹⁷⁴ independentlyrepresents a nitrogen atom or a carbon atom, each of D¹⁷¹ to D¹⁷⁶independently represents an atom selected from carbon, nitrogen, oxygen,sulfur and silicon, the bond between atoms in the 5-membered ring formedby D¹⁷¹ to D¹⁷³, A¹⁷¹ and A¹⁷² or by D¹⁷⁴ to D¹⁷⁶, A¹⁷³ and A¹⁷⁴represents a single bond or a double bond, each of D¹⁷¹ to D¹⁷⁶ whenthese can be further substituted may have a substituent, E¹⁷¹ representsa divalent linking group, each of S¹⁷¹ to S¹⁷⁴ independently representsa group represented by formula (I), each of n, m, k and l represents aninteger of 0 to 4, n+m+k+l is an integer of 1 to 4, and each S¹⁷¹, S¹⁷²,S¹⁷³ or S¹⁷⁴ may be the same as or different from every other S¹⁷¹,S¹⁷², S¹⁷³ or S¹⁷⁴).meanings as R¹⁵³ to R¹⁵⁸, E¹⁵¹, S¹⁵¹ to S¹⁵⁴, n, m, k and l in formula(15), and the preferred ranges are also the same.

Each of A¹⁷¹, A¹⁷², A¹⁷³ and A¹⁷⁴ independently represents a nitrogenatom or a carbon atom. A¹⁷¹ and A¹⁷² form an aromatic heterocyclic ringor an aromatic hydrocarbon ring together with D¹⁷¹ to D¹⁷³, and A¹⁷³ andA¹⁷⁴ form an aromatic heterocyclic ring or an aromatic hydrocarbon ringtogether with D¹⁷⁴ to D¹⁷⁶.

Each of D¹⁷¹ to D¹⁷³ and D¹⁷⁴ to D¹⁷⁶ independently represents an atomselected from carbon, nitrogen, oxygen, sulfur and silicon. The bondbetween atoms in the 5-membered ring formed by A¹⁷¹, A¹⁷² and D¹⁷¹ toD¹⁷³ or by A¹⁷³, A¹⁷⁴ and D¹⁷⁴ to D¹⁷⁶ is not particularly limited butmay be any combination of a single bond and a double bond. Each of D¹⁷¹to D¹⁷³ and D¹⁷⁴ to D¹⁷⁶ is preferably a carbon atom or a nitrogen atom.

In the 5-membered ring formed by A¹⁷¹, A¹⁷² and D¹⁷¹ to D¹⁷³ or by A¹⁷³,A¹⁷⁴ and D¹⁷⁴ to D¹⁷⁶, the number of nitrogen atoms is preferably from 1to 3, more preferably from 1 to 2.

Each of D¹⁷¹ to D¹⁷³ and D¹⁷⁴ to D¹⁷⁶ when these can be furthersubstituted may have a substituent selected from Substituent Group A.The substituents may combine with each other to form a condensed ring,and examples of the ring formed include a benzene ring, a pyridine ring,a pyrazine ring, a pyrimidine ring, a triazine ring, a pyridazine ring,a pyrrole ring, a pyrazole ring, an imidazole ring, a triazole ring, anoxazole ring, an oxadiazole ring, a thiazole ring, a thiadiazole ring, afuran ring, a thiophene ring, a selenophene ring, a silole ring, agermole ring and a phosphole ring.

The substituent thereof is preferably a substituted or unsubstitutedalkyl group, a cycloalkyl group, an aryl group, an amino group, analkoxy group, an aryloxy group, an acyl group, an alkoxycarbonyl group,an aryloxycarbonyl group, an acyloxy group, a sulfonylamino group, asulfamoyl group, a carbamoyl group, an alkylthio group, an arylthiogroup, a heterocyclic thio group, a sulfonyl group, a sulfinyl group, aureido group, a phosphoric acid amido group, a hydroxy group, a mercaptogroup, a halogen atom, a sulfo group, a carboxyl group, a nitro group, asulfino group, a heterocyclic group or a silyl group, more preferably asubstituted or unsubstituted alkyl group, a cycloalkyl group, an arylgroup, an amino group, an alkoxy group, an aryloxy group, a cyano group,a fluorine atom or a heterocyclic group, still more preferably asubstituted or unsubstituted alkyl group, a fluorine atom, a methoxygroup, an aryl group or a cyano group. In particular, the substituent ispreferably a substituted or unsubstituted alkyl group, a fluorine atomor a cyano group, and most preferably a methyl group, a trifluoromethylgroup, a fluorine atom or a cyano group.

The compound represented by formula (14) is preferably represented bythe following formula (18):

(In formula (18), each of A¹⁸¹ to A¹⁸⁶ independently represents anitrogen atom or a carbon atom, each of D¹⁸¹ to D¹⁸⁴ independentlyrepresents an atom selected from carbon, nitrogen, oxygen, sulfur andsilicon, the bond between atoms in the 5-membered ring formed by D¹⁸¹,D¹⁸², A¹⁸¹, the nitrogen atom and the carbon atom or by D¹⁸³, D¹⁸⁴,A¹⁸⁴, the nitrogen atom and the carbon atom represents a single bond ora double bond, each of D¹⁸¹ to D¹⁸⁴ when these can be furthersubstituted may have a substituent, each of Z¹⁸¹ and Z¹⁸² independentlyrepresents an aromatic heterocyclic ring or an aromatic hydrocarbonring, E¹⁸¹ represents a divalent linking group, each of S¹⁸¹ to S¹⁸⁴independently represents a group represented by formula (I), each of n,m, k and l represents an integer of 0 to 4, n+m+k+l is an integer of 1to 4, and each S¹⁸¹, S¹⁸², S¹⁸³ or S¹⁸⁴ may be the same as or differentfrom every other S¹⁸¹, S¹⁸², S¹⁸³ or S¹⁸⁴).

In formula (18), A¹⁸², A¹⁸³, A¹⁸⁵, A¹⁸⁶, Z¹⁸¹, Z¹⁸², E¹⁸¹, S¹⁸¹ to S¹⁸⁴,n, m, k and l have the same meanings as A¹⁴², A¹⁴³, A¹⁴⁵, A¹⁴⁶, Z¹⁴³,Z¹⁴⁴, E¹⁴¹, S¹⁴¹ to S¹⁴⁴, n, m, k and l in formula (14), and thepreferred ranges are also the same.

Each of D¹⁸¹, D¹⁸², D¹⁸³ and D¹⁸⁴ independently represents an atomselected from carbon, nitrogen, oxygen, sulfur and silicon. The bondbetween atoms in the 5-membered ring formed by D¹⁸¹, D¹⁸², A¹⁸¹, thenitrogen atom and the carbon atom or by D¹⁸³, D¹⁸⁴, A¹⁸⁴, the nitrogenatom and the carbon atom is not particularly limited but may be anycombination of a single bond and a double bond. Each of D¹⁸¹, D¹⁸², D¹⁸³and D¹⁸⁴ is preferably a carbon atom or a nitrogen atom.

In the 5-membered ring formed by D¹⁸¹, D¹⁸², A¹⁸¹, the nitrogen atom andthe carbon atom or by D¹⁸³, D¹⁸⁴, A¹⁸⁴. Also, the nitrogen atom and thecarbon atom, the number of nitrogen atoms is preferably from 1 to 3,more preferably from 1 to 2.

Each of D¹⁸¹, D¹⁸², D¹⁸³ and D¹⁸⁴ when these can be further substitutedmay have a substituent selected from Substituent Group A. Thesubstituents may combine with each other to form a condensed ring, andexamples of the ring formed include a benzene ring, a pyridine ring, apyrazine ring, a pyrimidine ring, a triazine ring, a pyridazine ring, apyrrole ring, a pyrazole ring, an imidazole ring, a triazole ring, anoxazole ring, an oxadiazole ring, a thiazole ring, a thiadiazole ring, afuran ring, a thiophene ring, a selenophene ring, a silole ring, agermole ring and a phosphole ring.

The substituent is preferably a substituted or unsubstituted alkylgroup, a cycloalkyl group, an aryl group, an amino group, an alkoxygroup, an aryloxy group, an acyl group, an alkoxycarbonyl group, anaryloxycarbonyl group, an acyloxy group, a sulfonylamino group, asulfamoyl group, a carbamoyl group, an alkylthio group, an arylthiogroup, a heterocyclic thio group, a sulfonyl group, a sulfinyl group, aureido group, a phosphoric acid amido group, a hydroxy group, a mercaptogroup, a halogen atom, a sulfo group, a carboxyl group, a nitro group, asulfino group, a heterocyclic group or a silyl group, more preferably asubstituted or unsubstituted alkyl group, a cycloalkyl group, an arylgroup, an amino group, an alkoxy group, an aryloxy group, a cyano group,a fluorine atom or a heterocyclic group, still more preferably asubstituted or unsubstituted alkyl group, a fluorine atom, a methoxygroup, an aryl group or a cyano group. In particular, the substituent ispreferably a substituted or unsubstituted alkyl group, a fluorine atomor a cyano group, and most preferably a methyl group, a trifluoromethylgroup, a fluorine atom or a cyano group.

The compound represented by formula (18) is preferably represented bythe following formula (19):

(In formula (19), each of A¹⁹¹ and A¹⁹² independently represents anitrogen atom or a carbon atom, each of D¹⁹¹ to D¹⁹⁴ independentlyrepresents an atom selected from carbon, nitrogen, oxygen, sulfur andsilicon, the bond between atoms in the 5-membered ring formed by D¹⁹¹,D¹⁹², A¹⁹¹, the nitrogen atom and the carbon atom or by D¹⁹³, D¹⁹⁴,A¹⁹⁴, the nitrogen atom and the carbon atom represents a single bond ora double bond, each of D¹⁹¹ to D¹⁹⁴ when these can be furthersubstituted may have a substituent, each of B¹⁹¹ to B¹⁹⁸ independentlyrepresents a nitrogen atom or C—R¹⁹⁹, R¹⁹⁹ represents a hydrogen atom ora substituent, each R¹⁹⁹ may be the same as or different from everyother R¹⁹⁹, E¹⁹¹ represents a divalent linking group, each of S¹⁹¹ toS¹⁹⁴ independently represents a group represented by formula (I), eachof n, m, k and l represents an integer of 0 to 4, n+m+k+l is an integerof 1 to 4, and each S¹⁹¹, S¹⁹², S¹⁹³ or S¹⁹⁴ may be the same as ordifferent from every other S¹⁹¹, S¹⁹², S¹⁹³ or S¹⁹⁴).

In formula (19), E¹⁹¹, S¹⁹¹ to S¹⁹⁴, n, m, k and l have the samemeanings as E¹⁸¹, S¹⁸¹ to S¹⁸⁴, n, m, k and l in formula (18), and thepreferred ranges are also the same.

Each of B¹⁹¹ to B¹⁹⁸ independently represents a nitrogen atom or C—R¹⁹⁷,and R¹⁹⁷ represents a hydrogen atom or a substituent. The combination ofB¹⁹¹ to B¹⁹⁸ is not particularly limited but out of B¹⁹¹ to B¹⁹⁴, thenumber of nitrogen atoms is preferably from 0 to 2, more preferably from0 to 1, and out of B¹⁹⁵ to B¹⁹⁸, the number of nitrogen atoms ispreferably from 0 to 2, more preferably from 0 to 1.

As for the substituent represented by R¹⁹⁷, those described asSubstituent Group A can be applied.

Each R¹⁹⁷ may be the same as or different from every other R¹⁹⁷. R¹⁹⁷may further have a substituent, and those described above as SubstituentGroup A can be applied to the substituent. Also, R¹⁹⁷'s may combine witheach other to form a condensed ring, and examples of the ring formedinclude a benzene ring, a pyridine ring, a pyrazine ring, a pyrimidinering, a triazine ring, a pyridazine ring, a pyrrole ring, a pyrazolering, an imidazole ring, a triazole ring, an oxazole ring, an oxadiazolering, a thiazole ring, a thiadiazole ring, a furan ring, a thiophenering, a selenophene ring, a silole ring, a germole ring and a phospholering.

R¹⁹⁷ is preferably a substituted or unsubstituted alkyl group, acycloalkyl group, an aryl group, an amino group, an alkoxy group, anaryloxy group, an acyl group, an alkoxycarbonyl group, anaryloxycarbonyl group, an acyloxy group, a sulfonylamino group, asulfamoyl group, a carbamoyl group, an alkylthio group, an arylthiogroup, a heterocyclic thio group, a sulfonyl group, a sulfinyl group, aureido group, a phosphoric acid amido group, a hydroxy group, a mercaptogroup, a halogen atom, a sulfo group, a carboxyl group, a nitro group, asulfino group, a heterocyclic group or a silyl group, more preferably asubstituted or unsubstituted alkyl group, a cycloalkyl group, an arylgroup, an amino group, an alkoxy group, an aryloxy group, a cyano group,a fluorine atom or a heterocyclic group, still more preferably asubstituted or unsubstituted alkyl group, a fluorine atom, a methoxygroup, an aryl group or a cyano group. In particular, the substituent ispreferably a substituted or unsubstituted alkyl group, a fluorine atomor a cyano group, and most preferably a methyl group, a trifluoromethylgroup, a fluorine atom or a cyano group.

The compound represented by formula (19) is preferably represented bythe following formula (20):

(In formula (20), each of R²⁰³ to R²⁰⁶ independently represents ahydrogen atom or a substituent, each of B²⁰¹ to B²⁰⁸ independentlyrepresents a nitrogen atom or C—R²⁰⁷, R²⁰⁷ represents a hydrogen atom ora substituent, each R²⁰⁷ may be the same as or different from everyother R²⁰⁷, E²⁰¹ represents a divalent linking group, each of S²⁰¹ toS²⁰⁴ independently represents a group represented by formula (I), andeach S²⁰¹, S²⁰², S²⁰³ or S²⁰⁴ may be the same as or different from everyother S²⁰¹, S²⁰², S²⁰³ or S²⁰⁴).

In formula (20), E²⁰¹, S²⁰¹ to S²⁰⁴, B²⁰¹ to B²⁰⁸, R²⁰³ to R²⁰⁷, n, m, kand l have the same meanings as E¹⁹¹, S¹⁹¹ to S¹⁹⁴, B¹⁹¹, to B¹⁹⁸, toR¹⁹¹ to R¹⁹⁷, n, m, k and l in formula (19), and the preferred rangesare also the same.

The compound represented by formula (19) is preferably represented bythe following formula (21):

(In formula (21), each of R²¹³ and R²¹⁴ independently represents ahydrogen atom or a substituent, each of R²¹⁵ and R²¹⁶ independentlyrepresents a hydrogen atom or a substituent, each of B²¹¹ to B²¹⁸independently represents a nitrogen atom or C—R²¹⁷, R²¹⁷ represents ahydrogen atom or a substituent, each R²¹⁷ may be the same as ordifferent from every other R²¹⁷, E²¹¹ represents a divalent linkinggroup, each of S²¹¹ to S²¹⁴ independently represents a group representedby formula (I), each of n, m, k and l represents an integer of 0 to 4,n+m+k+l is an integer of 1 to 4, and each S²¹¹, S²¹², S²¹³ or S²¹⁴ maybe the same as or different from every other S²¹¹, S²¹², S²¹³ or S²¹⁴).

In formula (21), E²¹¹, S²¹¹, S²¹⁴, n, m, k and l have the same meaningsas E¹⁷¹, S¹⁷¹ to S¹⁷⁴, n, m, k and l in formula (17), and the preferredranges are also the same.

Each of B²¹¹ to B²¹⁸ independently represents a nitrogen atom or C—R²¹⁷,and R²¹⁷ represents a hydrogen atom or a substituent. The combination ofB²¹¹ to B²¹⁸ is not particularly limited but out of B²¹¹ to B²¹⁴, thenumber of nitrogen atoms is preferably from 0 to 2, more preferably from0 to 1, and out of B²¹⁵ to B²¹⁸, the number of nitrogen atoms ispreferably from 0 to 2, more preferably from 0 to 1.

Each of R²¹³ to R²¹⁶ independently represents a hydrogen atom or mayhave a substituent selected from substituents including SubstituentGroup A. The substituent is preferably a substituted or unsubstitutedalkyl group, a cycloalkyl group, an aryl group, an amino group, analkoxy group, an aryloxy group, an acyl group, an alkoxycarbonyl group,an aryloxycarbonyl group, an acyloxy group, a sulfonylamino group, asulfamoyl group, a carbamoyl group, an alkylthio group, an arylthiogroup, a heterocyclic thio group, a sulfonyl group, a sulfinyl group, aureido group, a phosphoric acid amido group, a hydroxy group, a mercaptogroup, a halogen atom, a sulfo group, a carboxyl group, a nitro group, asulfino group, a heterocyclic group or a silyl group, more preferably asubstituted or unsubstituted alkyl group, a cycloalkyl group, an arylgroup, an amino group, an alkoxy group, an aryloxy group, a cyano group,a fluorine atom or a heterocyclic group, still more preferably asubstituted or unsubstituted alkyl group, a fluorine atom, a methoxygroup, an aryl group or a cyano group. In particular, the substituent ispreferably a substituted or unsubstituted alkyl group, a fluorine atomor a cyano group, and most preferably a methyl group, a trifluoromethylgroup, a fluorine atom or a cyano group.

Each of the compounds represented by formulae (1) to (21) may be apolymer compound having the compound in the main or side chain.

The polymer compound may be a homopolymer compound or a copolymer, andthe copolymer may be any of a random copolymer, an alternating copolymerand a block copolymer. In the case of a copolymer, the other monomer ispreferably a monomer having a charge transport function moiety. Examplesof the monomer having a charge transport function include a materialhaving in its partial structure a compound described later as the hostmaterial, the material contained in the hole transporting layer, or thematerial contained in the electron transporting material. A monomerhaving in its partial structure a compound described as the hostmaterial is preferred.

In the case of a polymer compound, the molecular weight is preferablyfrom 2,000 to less than 1,000,000, more preferably from 10,000 to lessthan 500,000, still more preferably from 10,000 to less than 100,000.

Specific examples of the compound represented by formula (1) for use inthe present invention are illustrated below, but the present inventionis not limited thereto.

Other specific examples are illustrated below.

These compounds can be synthesized by various known synthesis methodsdescribed, for example, in Org. Lett., 3, 2579-2581 (2001), Inorg.Chem., 30, 1685-1687 (1991), J. Am. Chem. Soc., Vol. 123, 4304 (2001),Inorg. Chem., Vol. 40, 1704-1711 (2001), Inorg. Chem., 41, 3055-3066(2002), and Eur. J. Org. Chem., 4, 695-709 (2004).

Furthermore, the above-described metal complex compounds can besynthesized by various techniques such as the method described inJournal of Organic Chemistry, 53, 786 (1988), G. R. Newkome et al., atpage 789, from left column, line 53 to right column, line 7, the methoddescribed at page 790, left column, lines 18 to 38, the method describedat page 790, right column, lines 19 to 30, a combination thereof, andthe method described in Chemische Berichte, 113, 2749 (1980), H. Lexy etal., at page 2752, liens 26 to 35.

For example, a ligand or a dissociation product thereof and a metalcompound are reacted with or without a solvent (for example, ahalogen-based solvent, an alcohol-based solvent, an ether-based solvent,an ester-based solvent, a ketone-based solvent, a nitrile-based solvent,an amide-based solvent, a sulfone-based solvent, a sulfoxide-basedsolvent or water) in the presence or absence of a base (variousinorganic or organic bases, for example, sodium methoxide, tert-butoxypotassium, triethylamine or potassium carbonate) at not higher than roomtemperature or under heating (in addition to normal heating, microwaveheating is also effective), whereby the compound can be obtained.

In another embodiment of the present invention, the metal complex havinga group represented by formula (I) is preferably a phosphorescent metalcomplex containing a monoanionic bidentate ligand represented by thefollowing formulae (A1) to (A4) and a metal having an atomic weight of40 or more.

Incidentally, in the formulae of ligands for use in the presentinvention, * is a coordination site to a metal, and each of the bondbetween E_(1a) and the metal and the bond between E_(1p) and the metalmay be individually either a covalent bond or a coordinate bond.

The bidentate ligand represented by the following formulae (A1) to (A4)is described below.

[Bidentate Ligand Represented by Formulae (A1) to (A4)]

(In formulae (1) to (4), each of E_(1a) to E_(1q) independentlyrepresents a carbon atom or a heteroatom, each of R_(1a) to R_(1i)independently represents a hydrogen atom or a substituent, provided thatat least one of R_(1a) to R_(1i) represents a group represented byformula (I), and each of the frameworks represented by formulae (A1) to(A4) has a structure with 18π-electrons in total).

At least one of R_(1a) to R_(1i) represents a group represented byformula (I).

As the group represented by formula (I) in R_(1a) to R_(1i),substituents a1 to a31 are preferred, a1, a2, a3, a5, a8, a9, a10, a12,a14, a15, a18, a19, a28, a29, a30 and a31 are more preferred, a2, a5,a9, a12, a18, a19, a28 and a29 are still more preferred, and a2, a5, a9and a12 are most preferred. This is presumed because all of bulkiness,rigidity and compactness are satisfied.

Preferably, at least one of R_(1a), R_(1b), R_(1d), R_(1e), R_(1g) andR_(1b) is a group represented by formula (I), and more preferably, atleast one of R_(1a), R_(1b), R_(1d) and R_(1e) is a group represented byformula (I). In formulae A1 and A2, still more preferably, at least oneof R_(1a), R_(1b) and R_(1d) is a group represented by formula (I), andyet still more preferably, at least one of R_(1a) and R_(1d) is a grouprepresented by formula (I). In formulae A3 and A4, still morepreferably, at least one of R_(1a), R_(1b) and R_(1d) is a grouprepresented by formula (I), and yet still more preferably, at least oneof R_(1a), R_(1c) and R_(1d) is a group represented by formula (I).

The bidentate ligand may combine with other ligands to form atridentate, tetradentate, a pentadentate or hexadentate ligand.

Each of E_(1a) to E_(1q) is selected from a carbon atom and a heteroatom, preferably selected from a carbon atom and a nitrogen atom. E_(1a)and E_(1p) are preferably different atoms. The metal complex has astructure with 18π-electrons.

The ring composed of E_(1a) to E_(1q) represents a 5-memberedheterocycle, more specifically, oxazole, thiazole, isoxazole,isothiazole, pyrrole, imidazole, pyrazole, triazole, or tetrazole,preferably imidazole or pyrazole, more preferably imidazole. This5-membered ring may form a condensed ring with other rings.

At least one of E_(1a) to E_(1e) preferably represents a nitrogen atom;more preferably, two or three of E_(1a) to E_(1e) represent a nitrogenatom; and still more preferably, two of E_(1a) to E_(1e) represent anitrogen atom. In the case where two of E_(1a) to E_(1e) represent anitrogen atom, preferably, two of E_(1a), E_(1d) and E_(1e) represent anitrogen atom; more preferably E_(1a) and E_(1d), or E_(1a) and E_(1e)represent a nitrogen atom; and still more preferably, E_(1a) and E_(1d)represent a nitrogen atom.

The ring formed by E_(1f) to E_(1k) is a 5- or 6-membered aromatichydrocarbon ring or heterocyclic ring, preferably a 6-membered ring,more preferably a 6-membered aromatic hydrocarbon ring. Specificexamples of the ring formed by E_(1f) to E_(1k) include benzene,oxazole, thiazole, isoxazole, isothiazole, oxadiazole, thiadiazole,furan, thiophene, pyrrole, imidazole, pyrazole, triazole, pyridine,pyrazine, pyrimidine, pyridazine and triazine. Among these, pyridine andbenzene are preferred, and benzene is more preferred.

The ring formed by E_(1l) to E_(1q) is a 5- or 6-membered aromatichydrocarbon ring or heterocyclic ring, preferably a 6-membered ring,still more preferably a 6-membered aromatic hydrocarbon ring. Specificexamples of the ring formed by E_(1l) to E_(1q) include benzene,oxazole, thiazole, isoxazole, isothiazole, oxadiazole, thiadiazole,furan, thiophene, pyrrole, imidazole, pyrazole, triazole, pyridine,pyrazine, pyrimidine, pyridazine and triazine. Among these, pyridine andbenzene are preferred, and benzene is more preferred.

Each of R_(1a) to R_(1i) independently represents a hydrogen atom or asubstituent. The substituent is preferably a group selected fromSubstituent Group Z.

Specific examples of Substituent Group Z include an alkyl group, analkenyl group, an alkynyl group, an aryl group, a heteroaryl group, anamino group, an alkoxy group, an aryloxy group, a heterocyclic oxygroup, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group,an acyloxy group, an acylamino group, an alkoxycarbonylamino group, anaryloxycarbonylamino group, a sulfonylamino group, a sulfamoyl group, acarbamoyl group, an alkylthio group, an arylthio group, a heteroarylthiogroup, a sulfonyl group, a sulfinyl group, a ureido group, a phosphoricacid amido group, a hydroxy group, a mercapto group, a halogen atom, acyano group, a sulfo group, a carboxyl group, a nitro group, ahydroxamic acid group, a sulfino group, a hydrazino group, an iminogroup, a heterocyclic group except for heteroaryl group, a silyl group,a silyloxy group and a deuterium atom. These substituents may further besubstituted with other substituents.

Here, the alkyl group is preferably an alkyl group having a carbonnumber of 1 to 30, more preferably from 1 to 20, still more preferablyfrom 1 to 10, and examples thereof include methyl, ethyl, n-propyl,isopropyl, n-butyl, tert-butyl, n-octyl, n-nonyl, n-decyl, n-dodecyl,n-octadecyl, n-hexadecyl, cyclopropyl, cyclobutyl, cyclopentyl,cyclohexyl, cyclooctyl, 1-adamantyl and trifluoromethyl.

The alkenyl group is preferably an alkenyl group having a carbon numberof 2 to 30, more preferably from 2 to 20, still more preferably from 2to 10, and examples thereof include vinyl, allyl, 1-propenyl,1-isopropenyl, 1-butenyl, 2-butenyl and 3-pentenyl.

The alkynyl group is preferably an alkynyl group having a carbon numberof 2 to 30, more preferably from 2 to 20, still more preferably from 2to 10, and examples thereof include ethynyl, propargyl, 1-propynyl and3-pentynyl.

The aryl group indicates an aromatic hydrocarbon monoradical. In thecase where the aryl group is substituted, preferred examples of thesubstituent include a fluoro group, a hydrocarbon substituent, aheteroatom-substituted hydrocarbon substituent and a cyano group. Thearyl group is preferably an aryl group having a carbon number of 6 to30, more preferably from 6 to 20, still more preferably from 6 to 12,and examples thereof include phenyl, o-methylphenyl, m-methylphenyl,p-methylphenyl, 2,6-xylyl, p-cumenyl, mesityl, naphthyl and anthranyl.

The heteroaryl group indicates an aromatic heterocyclic monoradical. Inthe case where the heteroaryl group is substituted, preferred examplesof the substituent include a fluoro group, a hydrocarbon substituent, aheteroelement-substituted hydrocarbon substituent and a cyano group.Examples of the heterocyclic group include imidazolyl, pyrazolyl,pyridyl, pyrazyl, pyrimidyl, triazinyl, quinolyl, isoquinolinyl,pyrrolyl, indolyl, furyl, thienyl, benzoxazolyl, benzimidazolyl,benzothiazolyl, carbazolyl and azepinyl.

The amino group is preferably an amino group having a carbon number of 0to 30, more preferably from 0 to 20, still more preferably from 0 to 10,and examples thereof include amino, methylamino, dimethylamino,diethylamino, dibenzylamino, diphenylamino and ditolylamino.

The alkoxy group is preferably an alkoxy group having a carbon number of1 to 30, more preferably from 1 to 20, still more preferably from 1 to10, and examples thereof include methoxy, ethoxy, butoxy and2-ethylhexyloxy.

The aryloxy group is preferably an aryloxy group having a carbon numberof 6 to 30, more preferably from 6 to 20, still more preferably from 6to 12, and examples thereof include phenyloxy, 1-naphthyloxy and2-naphthyloxy.

The heterocyclic oxy group is preferably a heterocyclic oxy having acarbon number of 1 to 30, more preferably from 1 to 20, still morepreferably from 1 to 12, and examples thereof include pyridyloxy,pyrazyloxy, pyrimidyloxy and quinolyloxy.

The acyl group is preferably an acyl group having a carbon number of 2to 30, more preferably from 2 to 20, still more preferably from 2 to 12,and examples thereof include acetyl, benzoyl, formyl and pivaloyl.

The alkoxycarbonyl group is preferably an alkoxycarbonyl group having acarbon number of 2 to 30, more preferably from 2 to 20, still morepreferably from 2 to 12, and examples thereof include methoxycarbonyland ethoxycarbonyl.

The aryloxycarbonyl group is preferably an aryloxycarbonyl group havinga carbon number of 7 to 30, more preferably from 7 to 20, still morepreferably from 7 to 12, and examples thereof include phenyloxycarbonyl.

The acyloxy group is preferably an acyloxy group having a carbon numberof 2 to 30, more preferably from 2 to 20, still more preferably from 2to 10, and examples thereof include acetoxy and benzoyloxy.

The acylamino group is preferably an acylamino group having a carbonnumber of 2 to 30, more preferably from 2 to 20, still more preferablyfrom 2 to 10, and examples thereof include acetylamino and benzoylamino.

The alkoxycarbonylamino group is preferably an alkoxycarbonylamino grouphaving a carbon number of 2 to 30, more preferably from 2 to 20, stillmore preferably from 2 to 12, and examples thereof includemethoxycarbonylamino.

The aryloxycarbonylamino group is preferably an aryloxycarbonylaminogroup having a carbon number of 7 to 30, more preferably from 7 to 20,still more preferably from 7 to 12, and examples thereof includephenyloxycarbonylamino.

The sulfonylamino group is preferably a sulfonylamino group having acarbon number of 1 to 30, more preferably from 1 to 20, still morepreferably from 1 to 12, and examples thereof includemethanesulfonylamino and benzenesulfonylamino.

The sulfamoyl group is preferably a sulfamoyl group having a carbonnumber of 0 to 30, more preferably from 0 to 20, still more preferablyfrom 0 to 12, and examples thereof include sulfamoyl, methylsulfamoyl,dimethylsulfamoyl and phenylsulfamoyl.

The carbamoyl group is preferably a carbamoyl group having a carbonnumber of 1 to 30, more preferably from 1 to 20, still more preferablyfrom 1 to 12, and examples thereof include carbamoyl, methylcarbamoyl,diethylcarbamoyl and phenylcarbamoyl.

The alkylthio group is preferably an alkylthio group having a carbonnumber of 1 to 30, more preferably from 1 to 20, still more preferablyfrom 1 to 12, and examples thereof include methylthio and ethylthio.

The arylthio group is preferably an arylthio group having a carbonnumber of 6 to 30, more preferably from 6 to 20, still more preferablyfrom 6 to 12, and examples thereof include phenylthio.

The heteroarylthio group is preferably a heteroarylthio group having acarbon number of 1 to 30, more preferably from 1 to 20, still morepreferably from 1 to 12, and examples thereof include pyridylthio,2-benzimidazolylthio, 2-benzoxazolylthio and 2-benzothiazolylthio.

The sulfonyl group is preferably a sulfonyl group having a carbon numberof 1 to 30, more preferably from 1 to 20, still more preferably from 1to 12, and examples thereof include mesyl, tosyl andtrifluoromethanesulfonyl.

The sulfinyl group is preferably a sulfinyl group having a carbon numberof 1 to 30, more preferably from 1 to 20, still more preferably from 1to 12, and examples thereof include methanesulfinyl and benzenesulfinyl.

The ureido group is preferably a ureido group having a carbon number of1 to 30, more preferably from 1 to 20, still more preferably from 1 to12, and examples thereof include ureido, methylureido and phenylureido.

The phosphoric acid amido group is preferably a phosphoric acid amidogroup having a carbon number of 1 to 30, more preferably from 1 to 20,still more preferably from 1 to 12, and examples thereof includediethylphosphoric acid amido and phenylphosphoric acid amido.

Examples of the halogen atom include fluorine atom, chlorine atom,bromine atom and iodine atom.

The heterocyclic group except for heteroaryl group is preferably aheterocyclic group having a carbon number of 1 to 30, more preferablyfrom 1 to 12. The heteroatom is, for example, nitrogen atom, oxygen atomor sulfur atom. Specific examples of the heterocyclic group includepiperidyl, morpholino and pyrrolidyl.

The silyl group is preferably a silyl group having a carbon number of 3to 40, more preferably from 3 to 30, still more preferably from 3 to 24,and examples thereof include trimethylsilyl, triethylsilyl,triisopropylsilyl, dimethyl-tert-butylsilyl, dimethylphenylsilyl,diphenyl-tert-butylsilyl, triphenylsilyl, tri-1-naphthylsilyl andtri-2-naphthylsilyl.

The silyloxy group is preferably a silyloxy group having a carbon numberof 3 to 40, more preferably from 3 to 30, still more preferably from 3to 24, and examples thereof include trimethylsilyloxy andtriphenylsilyloxy.

Each of R_(1a) to R_(1i) is preferably a hydrogen atom, a hydrocarbonsubstituent (preferably an alkyl group, a cycloalkyl group or an arylgroup), a cyano group, a fluoro group, OR_(2a), SR_(2a), NR_(2a)R_(2b),BR_(2a)R_(2b) or SiR_(2a)R_(2b)R_(2c). Each of R_(2a) to R_(2c) isindependently a hydrocarbon substituent or a hydrocarbon substituentsubstituted with a heteroatom. Two of R_(1a) to R_(1i) and R_(2a) toR_(2c) may combine with each other to form a saturated or unsaturated,aromatic or non-aromatic ring.

At least one of R_(1a) to R_(1i) is preferably an aryl group having adihedral angle of 70° or more with respect to the mother structure, morepreferably a substituent represented by the following formula ss-1,still more preferably a 2,6-disubstituted aryl group, and it is mostpreferred that R_(1b) is a 2,6-disubstituted aryl group.

(In formula ss-1, each of Ra, Rb and Rc independently represents ahydrogen atom, an alkyl group or an aryl group, and the number of Rc isfrom 0 to 3).

The alkyl group represented by Ra, Rb and Re is preferably an alkylgroup having a carbon number of 1 to 30, more preferably from 1 to 20,still more preferably from 1 to 10, and examples thereof include methyl,ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, n-octyl, n-nonyl,n-decyl, n-dodecyl, n-octadecyl, n-hexadecyl, cyclopropyl, cyclobutyl,cyclopentyl, cyclohexyl, cyclooctyl, 1-adamantyl and trifluoromethyl.Among these, a methyl group and an isopropyl group are preferred.

The aryl group represented by Ra, Rb and Re is preferably an aryl grouphaving a carbon number of 6 to 30, more preferably from 6 to 20, stillmore preferably from 6 to 12, and examples thereof include phenyl,o-methylphenyl, m-methylphenyl, p-methylphenyl, 2,6-xylyl, p-cumenyl,mesityl, naphthyl and anthranyl. Among these, a phenyl group, a2,6-xylyl group and a mesityl group are preferred, and a phenyl group ismore preferred.

At least one of Ra and Rb is preferably selected from an alkyl group andan aryl group; more preferably, at least one of Ra and Rb is selectedfrom an alkyl group; still more preferably, both Ra and Rb are an alkylgroup; and most preferably, both Ra and Rb are a methyl group or anisopropyl group.

The 2,6-disubstituted aryl group is preferably a 2,6-dimethylphenylgroup, a 2,4,6-trimethylphenyl group, a 2,6-diisopropylphenyl group, a2,4,6-diisopropylphenyl group, a 2,6-dimethyl-4-phenylphenyl group, a2,6-dimethyl-4-(2,6-dimethylpyridin-4-yl)phenyl group, a2,6-diphenylphenyl group, a 2,6-diphenyl-4-isopropylphenyl group, a2,4,6-triphenylphenyl group, a2,6-diisopropyl-4-(4-isopropylphenyl)phenyl group, a2,6-diisopropyl-4-(3,5-dimethylphenyl)phenyl group, a2,6-diisopropyl-4-(pyridin-4-yl)phenyl group or a2,6-di-(3,5-dimethylphenyl)phenyl group,

The number of Re is preferably 0 or 1. Each Rc may be the same as ordifferent from every other Re.

At least one of R_(1a) and R_(1b) is preferably an electron-donatinggroup; more preferably, R_(1a) is an electron-donating group; and stillmore preferably, R_(1a) is a methyl group.

The hydrocarbon substituent indicates a monovalent or divalent, chain,branched or cyclic substituent composed of only a carbon atom and ahydrogen atom.

Examples of the monovalent hydrocarbon substituent include an alkylgroup having a carbon number of 1 to 20; an alkyl group having a carbonnumber of 1 to 20 substituted with one or more groups selected from analkyl group having a carbon number of 1 to 20, a cycloalkyl group havinga carbon number of 3 to 8 and an aryl group; a cycloalkyl group having acarbon number of 3 to 8; a cycloalkyl group having a carbon number of 3to 8 substituted with one or more groups selected from an alkyl grouphaving a carbon number of 1 to 20, a cycloalkyl group having a carbonnumber of 3 to 8 and an aryl group; an aryl group having a carbon numberof 6 to 18; and an aryl group substituted with one or more groupsselected from an alkyl group having a carbon number of 1 to 20, acycloalkyl group having a carbon number of 3 to 8 and an aryl group.

Examples of the divalent hydrocarbon group include —CH₂—, —CH₂CH₂—,—CH₂CH₂CH₂— and 1,2-phenylene group.

The metal in the phosphorescent metal complex for use in the presentinvention is preferably a metal having an atomic weight of 40 or more,which belongs to Groups 8 to 10 of the periodic table. Also, the metalis preferably a nonradioactive metal. The metal in the phosphorescentmetal complex for use in the present invention is preferably any one ofRe, Ru, Os, Rh, Ir, Pd, Pt, Cu and Au, more preferably Os, Ir or Pt,still more preferably Ir or Pt, and in view of high luminous efficiency,high complex stability and control of the carrier balance in thehole/electron transporting inside of the light emitting layer, mostpreferably Ir.

In the present invention, the metal complex composed of a ligand in theformula may be configured by a primary ligand or its tautomer and anauxiliary ligand or its tautomer, or all ligands of the metal complexmay be composed of only a partial structure represented by the primaryligand or its tautomer.

If desired, the metal complex may have, as an auxiliary ligand, a ligand(sometimes referred to as a coordination compound) known as a so-calledligand to one skilled in the art and used for the formation ofconventionally known metal complexes.

From the standpoint of successfully obtaining the effects described inthe present invention, the complex is preferably composed of one kind ortwo kinds of ligands, more preferably one kind of a ligand. In view ofeasiness of synthesis when introducing a reactive group into the complexmolecule, it is also preferred that the complex is composed of two kindsof ligands.

As for the ligand used in conventionally known metal complexes, variousligands are known, but examples thereof include ligands described in H.Yersin, Photochemistry and Photophysics of Coordination Compounds,Springer-Verlag (1987), and Akio Yamamoto, Yuki Kinzoku Kagaku—Kiso toOvo—(Organic Metal Chemistry—Basic and Application—), Shokabo (1982)(for example, a halogen ligand (preferably chlorine ligand), a cyanoligand, a phosphine ligand, a nitrogen-containing heteroaryl ligand(e.g., bipyridyl, phenanthroline), and a diketonate ligand (e.g.,acetylacetone)). Diketones and picolinic acid derivatives are preferred.

Specific examples of the auxiliary ligand are set forth below, but thepresent invention is not limited thereto.

(M₁ represents a metal atom having an atomic weight of 40 or more, andeach of Rx, Ry and Rz independently represents a hydrogen atom or asubstituent).

The monoanionic bidentate ligand represented by any one of formulae (A1)to (A4) is preferably a monoanionic bidentate ligand represented byformula (A1) or (A3).

The monoanionic bidentate ligand represented by formula (A1) or (A3) ispreferably a monoanionic bidentate ligand represented by formula (A1-1)or (A3-1) or represented by formula (A1-2) or (A3-2).

(In formulae (A1-1), (A3-1), (A1-2) and (A3-2), each of E_(1f) to E_(1q)independently represents a carbon atom or a heteroatom, each of R_(1a)to R_(1i) independently represents a hydrogen atom or a substituent,provided that at least one of R_(1a) to R_(1i) represents a grouprepresented by formula (I), and each of the frameworks represented byformulae (A1-1), (A3-1), (A1-2) and (A3-2) has a structure with18π-electrons in total).

In formulae (A1-1), (A3-1), (A1-2) and (A3-2), the definitions of E_(1f)to E_(1y) and R_(1a) to R_(1i) are the same as those of E_(1f) to E_(1q)and R_(1a) to R_(1i) in formulae (A1) and (A3), and the preferred rangesare also the same.

The monoanionic bidentate ligand represented by formula (A1-1), (A3-1),(A1-2) or (A3-2) is preferably a monoanionic bidentate ligandrepresented by formula (A1-3) or (A3-3):

(In formulae (A1-3) and (A3-3), each of E_(1f) to E_(1k) independentlyrepresents a carbon atom or a heteroatom, each of R_(1a) to R_(1i)independently represents a hydrogen atom or a substituent, provided thatat least one of R_(1a) to R_(1i) represents a group represented byformula (I), and each of the frameworks represented by formulae (A1-3)and (A3-3) has a structure with 18π-electrons in total).

In formulae (A1-3) and (A3-3), the definitions of E_(1f) to E_(1q) andR_(1a) to R_(1i) are the same as those of E_(1f) to E_(1q) and R_(1a) toR_(1i) in formulae (A1-1), (A3-1), (A1-2) and (A3-2), and preferredranges are also the same.

The phosphorescent metal complex containing a monoanionic bidentateligand represented by formula (A1-3) or (A3-3) and a metal having anatomic weight of 40 or more is preferably an iridium complex representedby formula (A9):

(In formula (9), each of R_(1a) to R_(1i) independently represents ahydrogen atom or a substituent, provided that at least one of R_(1a) toR_(1i) represents a group represented by formula (I), X—Y represents atleast one monoanionic bidentate ligand selected from (1-1) to (1-14),and n represents an integer of 1 to 3).

In formula (A9), preferred ranges of R_(1a) to R_(1i) are the same aspreferred ranges of R_(1a) to R_(1i) in formula (A1).

X-Y represents an auxiliary ligand, and n represents an integer of 1 to3 and is preferably n=3. As for the auxiliary ligand, specifically, thesame ligands as described above can be suitably used, and anacetylacetonate ligand and a substituted acetylacetonate ligand analogare preferred.

From the standpoint of easiness of synthesis, n is preferably 3, but itis also preferred in view of cost that n is 1 or 2, because the ligandcan be replaced by an inexpensive auxiliary ligand.

The metal complex represented by formula (A9) is preferably a metalcomplex represented by formula (A10). In the formula, R_(1e) is asubstituent represented by formula (I).

More specifically, formulae (A1) and (A3) are preferably the followingstructures. Among these, X-1, X-4, X-32, X-33, X-38, X-39, X-46, X-51,X-52, X-53, X-55, X-56, X-57, X-58, X-59, X-62, X-63, X-64, X-66, X-67and X-68 are more preferred, and X-46, X-52, X-53, X-56, X-57, X-58,X-62 and X-66 are most preferred.

R^(1a) to R^(1i) have the same meanings as in formula (A1), and it ispreferred that all are a hydrogen atom.

The phosphorescent metal complex containing a monoanionic bidentateligand represented by formulae (A1) to (A4) and a metal having an atomicweight of 40 or more can be synthesized by various methods such asmethods described in US2007/0190359 and US2008/0297033.

For example, a ligand or a dissociation product thereof and a metalcompound are reacted with or without a solvent (for example, ahalogen-based solvent, an alcohol-based solvent, an ether-based solvent,an ester-based solvent, a ketone-based solvent, a nitrile-based solvent,an amide-based solvent, a sulfone-based solvent, a sulfoxide-basedsolvent or water) in the presence or absence of a base (variousinorganic or organic bases, for example, sodium methoxide, tert-butoxypotassium, triethylamine or potassium carbonate) at not higher than roomtemperature or under heating (in addition to normal heating, microwaveheating is also effective), whereby the complex can be obtained.Specifically, XM-64 can be synthesized starting from7-methyl-imidazophenanthridine according to the synthesis methoddescribed in US2007/0190359, paragraphs [0132] to [0134]. Also, XM-63can be synthesized according to the synthesis method described inUS2008/0297033, paragraphs [0281] to [0287].

In the present invention, the metal complex having a group representedby formula (I) is not limited in its use and may be contained in anylayer within the organic layer. The layer into which the metal complexhaving a group represented by formula (I) is introduced may be any oneof a light emitting layer, a hole injection layer, a hole transportinglayer, an electron transporting layer, an electron injection layer, anexciton blocking layer and a charge blocking layer.

The present invention also relates to a composition containing the metalcomplex having a group represented by formula (I). By using acomposition containing a metal complex having a saturated 5- to8-membered ring-containing group, an organic electroluminescence devicemore excellent in the external quantum efficiency can be obtained.

In the present invention, in order to more reduce the change inchromaticity at high-temperature driving, the metal complex having agroup represented by formula (I) is preferably incorporated into a lightemitting layer.

The present invention also related to a light emitting layer containingthe metal complex having a group represented by formula (I).

In the case of incorporating the metal complex having a grouprepresented by formula (I) into a light emitting layer, the metalcomplex is preferably contained in an amount of 0.1 to 50 mass %, morepreferably from 1 to 50 mass %, still more preferably from 2 to 40 mass%, based on the total mass of the light emitting layer.

Also, in the case of incorporating the metal complex having a grouprepresented by formula (I) into a layer other than a light emittinglayer, the metal complex is preferably contained in an amount of 0.1 to100 mass %, more preferably from 10 to 100 mass %, still more preferablyfrom 30 to 100 mass %.

[Organic Electroluminescence Device]

The device of the present invention is described in detail below.

The organic electroluminescence device of the present invention is anorganic electroluminescence device including a substrate having thereona pair of electrodes and at least one organic layer between theelectrodes, the organic layer containing a light emitting layer,

wherein any one layer of the organic layer contains a meal complexhaving a group represented by formula (I).

In the organic electroluminescence device of the present invention, thelight emitting layer is an organic layer, and the device may have aplurality of organic layers.

In view of property of the luminescence device, at least one electrodeof the anode and the cathode is preferably transparent or translucent.

FIG. 1 shows one example of the configuration of the organicelectroluminescence device of the present invention. In the organicelectroluminescence device 10 of the present invention shown in FIG. 1,a light emitting layer 6 is sandwiched between an anode 3 and a cathode9 on a supporting substrate 12. More specifically, a hole injectionlayer 4, a hole transporting layer 5, the light emitting layer 6, a holeblocking layer 7 and an electron transporting layer 8 are stacked inthis order between the anode 3 and the cathode 9.

<Configuration of Organic Layer>

The layer configuration of the organic layer is not particularly limitedand may be appropriately selected according to the use and purpose ofthe organic electroluminescence device but is preferably formed on thetransparent electrode or back plate. In this case, the organic layer isformed on the front surface or one surface of the transparent electrodeor back plate.

The shape, size, thickness and the like of the organic layer are notparticularly limited and may be appropriately selected according to thepurpose.

Specific examples of the layer configuration include the followingconfigurations, but the present invention is not limited thereto.

-   -   Anode/hole transporting layer/light emitting layer/electron        transporting layer/cathode    -   Anode/hole transporting layer/light emitting layer/blocking        layer/electron transporting layer/cathode    -   Anode/hole transporting layer/light emitting layer/blocking        layer/electron transporting layer/electron injection        layer/cathode    -   Anode/hole injection layer/hole transporting layer/light        emitting layer/blocking layer/electron transporting        layer/cathode    -   Anode/hole injection layer/hole transporting layer/light        emitting layer/blocking layer/electron transporting        layer/electron injection layer/cathode

The device configuration, substrate, cathode and anode of an organicelectroluminescence device are described in detail, for example, inJP-A-2008-270736, and the matters described therein can be applied tothe present invention.

<Substrate>

The substrate used in the invention is preferably a substrate whichcauses neither scattering nor damping of light emitted from the organiclayer. When the substrate is made from an organic material, it ispreferable that the organic material has excellent heat resistance,dimensional stability, solvent resistance, electrical insulation andworkability.

<Anode>

The anode is usually sufficient if it has a function as an electrode ofsupplying a hole to the organic layer. The shape, structure, size andthe like thereof are not particularly limited, and the anode materialmay be appropriately selected from known electrode materials accordingto the use or purpose of the luminescence device. As described above,the anode is usually provided as a transparent anode.

<Cathode>

The cathode is usually sufficient if it has a function as an electrodeof injecting an electron in the organic layer. The shape, structure,size and the like thereof are not particularly limited, and the cathodematerial may be appropriately selected from known electrode materialsaccording to the use or purpose of the luminescence device.

As for the substrate, the anode and the cathode, the matters describedin JP-A-2008-270736, paragraphs [0070] to [0089] can be applied to thepresent invention.

<Organic Layer>

The organic layer for use in the present invention is described below.

—Formation of Organic Layer—

In the organic electroluminescence device of the present invention, eachorganic layer may be suitably formed by any of a dry deposition methodsuch as vapor deposition and sputtering, a transfer method, a printingmethod and the like.

(Light Emitting Layer)

<Light Emitting Material>

The light emitting material for use in the present invention ispreferably a metal complex having a group represented by formula (I).

The light emitting material in the light emitting layer is generallycontained in the light emitting layer, based on the mass of allcompounds forming the light emitting layer, in an amount of 0.1 to 50mass %, and in view of durability and external quantum efficiency,preferably in an amount of from 1 to 50 mass %, still more preferablyfrom 2 to 40 mass %.

The thickness of the light emitting layer is not particularly limitedbut usually, the thickness is preferably from 2 to 500 nm, and in viewof external quantum efficiency, more preferably from 3 to 200 nm, stillmore preferably from 5 to 100 nm.

In the device of the present invention, the light emitting layer may becomposed of only a light emitting material or may have a mixed layerconfiguration of a host material and a light emitting material. Thelight emitting material may be either a fluorescent material or aphosphorescent material and as for the dopant, one kind of a dopant ortwo or more kinds of dopants may be used. The host material ispreferably a charge transport material. As for the host material, onekind of a host material or two or more kinds of host materials may beused, and examples of this configuration include a configuration wherean electron transporting host material and a hole transporting hostmaterial are mixed. Also, the light emitting layer may contain amaterial having no charge transport property and being incapable ofproducing luminescence.

Furthermore, the light emitting layer may be a single layer or amultilayer composed of two or more layers. In the case of a plurality oflight emitting layers, the metal complex having a group represented byformula (I) may be contained in two or more light emitting layers. Also,respective light emitting layers may produce luminescence in differentcolors.

As regards the composition of the present invention, for example, theabove-described components constituting the light emitting layer may beadded to the light emitting material having a substituent represented byformula (1) of the present invention. It is also preferred to furtheradd a compound represented by formula (VI) described later.

<Host Material>

Examples of the host material contained in the light emitting layerinclude a compound having a carbazole structure, a compound having anazacarbazole structure, a compound having an indole structure, acompound having an azaindole structure, a compound having a diarylaminestructure, a compound having a pyridine structure, a compound having apyrazine structure, a compound having a triazine structure, a compoundhaving an arylsilane structure, and the materials exemplified later inthe paragraphs of hole injection layer, hole transporting layer,electron injection layer and electron transporting layer. Among these, acompound having a carbazole structure and a compound having an indolestructure are preferred.

Examples thereof include pyrrole, indole, carbazole (including CBP(4,4′-di(9-carbazolyl)biphenyl)), azaindole, azacarbazole, triazole,oxazole, oxadiazole, pyrazole, imidazole, thiophene, polyarylalkane,pyrazoline, pyrazolone, phenylenediamine, arylamine, amino-substitutedchalcone, styrylanthracene, fluorenone, hydrazone, stilbene, silazane,aromatic tertiary amine compounds, styrylamine compounds, porphyrincompounds, polysilane compounds, poly(N-vinylcarbazole), anilinecopolymers, thiophene oligomers, oligomers of conductive polymers likepolythiophene, organic silanes, carbon film, pyridine, pyrimidine,triazine, anthraquinodimethane, anthrone, diphenylquinone, thiopyrandioxide, carbodiimide, fluorelenylidenemethane, di styrylpyrazine,fluoro-substituted aromatic compounds, tetracarboxylic acid anhydridesof condensed aromatic ring compounds such as naphthalene and perylene,phthalocyanine, various kinds of metal complexes, typified by metalcomplexes of 8-quinolinol derivatives and metal complexes whose ligandsare metallo-phthalocyanines, benzoxazole or benzothiazole molecules, andderivatives of the above-recited metal complexes (e.g. those replacedwith substituents or those condensed with other rings).

In view of color purity, luminous efficiency and drive durability, thelowest triplet excitation energy (T₁ energy) of the host material in thelight emitting layer for use in the present invention is preferablyhigher than the T₁ energy of the phosphorescent material.

In the present invention, the content of the host compound is notparticularly limited but in view of luminous efficiency and drivevoltage, the content is preferably from 15 to 95 mass % based on themass of all compounds forming the light emitting layer.

The thickness of the light emitting layer is not particularly limitedbut usually, the thickness is preferably from 1 to 500 nm, morepreferably from 5 to 200 nm, still more preferably from 10 to 100 nm.

(Fluorescent Material)

Examples of a fluorescent material usable in the invention includebenzoxazole derivatives, benzimidazole derivatives, benzothiazolederivatives, styrylbenzene derivatives, polyphenyl derivatives,diphenylbutadiene derivatives, tetraphenylbutadiene derivatives,naphthalimide derivatives, coumarin derivatives, condensed aromaticcompounds, perinone derivatives, oxadiazole derivatives, oxazinederivatives, aldazine derivatives, pyralidine derivatives,cyclopentadiene derivatives, bisstyrylanthracene derivatives,quinacridone derivatives, pyrrolopyridine derivatives,thiadiazolopyridine derivatives, cyclopentadiene derivatives,styrylamine derivatives, diketopyrrolopyrrole derivatives, aromaticdimethylidyne derivatives, various kinds of complexes typified bycomplexes of 8-quinolinol derivatives and complexes of pyrromethenederivatives, polymeric compounds such as polythiophene, polyphenyleneand polyphenylenevinylene, and compounds like organic silanederivatives.

(Phosphorescent Material)

Examples of the phosphorescent material which can be used in the presentinvention include, other than the metal complex having a grouprepresented by formula (I), phosphorescent compounds described in patentdocuments such as U.S. Pat. Nos. 6,303,238B1, 6,097,147, WO 00/57676, WO00/70655, WO 01/08230, WO 01/39234A2, WO 01/41512A1, WO 02/02714A2, WO02115645A1, WO 02/44189A1, WO 05/19373A2, JP-A-2001-247859,JP-A-2002-302671, JP-A-2002-117978, JP-A-2003-133074, JP-A-2002-235076,JP-A-2003-123982, JP-A-2002-170684, EP 1211257, JP-A-2002-226495,JP-A-2002-234894, JP-A-2001-247859, JP-A-2001-298470, JP-A-2002-173674,JP-A-2002-203678, JP-A-2002-203679, JP-A-2004-357791, JP-A-2006-256999,JPA-2007-19462, JP-A-2007-84635 and JP-A-2007-96259. Examples ofluminescent dopants which are far preferred among those compoundsinclude the Ir complexes, the Pt complexes, the Cu complexes, the Recomplexes, the W complexes, the Rh complexes, the Ru complexes, the Pdcomplexes, the Os complexes, the Eu complexes, the Tb complexes, the Gdcomplexes, the Dy complexes and the Ce complexes. Of these complexes, Ircomplexes, the Pt complexes and the Re complexes are particularlypreferable, notably Ir complexes, the Pt complexes and the Re complexeseach having at least one kind of coordination bond selected frommetal-carbon, metal-nitrogen, metal-oxygen and metal-sulfur coordinatebonds. In terms of luminous efficiency, durability under driving,chromaticity and so on, the Ir complexes, the Pt complexes and the Recomplexes each having a polydentate ligand, including a tridentateligand or higher, are preferred over the others.

The content of the phosphorescent material in the light emitting layeris preferably from 0.1 to 50 mass %, more preferably from 0.2 to 50 mass%, still more preferably from 0.3 to 40 mass %, and most preferably from20 to 30 mass %, based on the total mass of the light emitting layer.

The content of the phosphorescent material (the metal complex having agroup represented by formula (I) and/or a phosphorescent material usedin combination) which can be used in the present invention is preferablyfrom 0.1 to 50 mass %, more preferably from 1 to 40 mass %, and mostpreferably from 5 to 30 mass %, based on the total mass of the lightemitting layer. In particular, within the range of 5 to 30 mass %, thechromaticity of luminescence of the organic electroluminescence deviceis small in the dependency on the concentration of the phosphorescentmaterial added.

The organic electroluminescence device of the present invention mostpreferably contains at least one kind of the compound (I) (the metalcomplex having a group represented by formula (I)) in an amount of 5 to30 mass % based on the total mass of the light emitting layer.

The organic electroluminescence device preferably further contains ahydrocarbon compound, and it is more preferred to contain a hydrocarboncompound in a light emitting layer.

The hydrocarbon compound is preferably a compound represented by thefollowing formula (VI).

By appropriately using the compound represented by formula (VI) togetherwith the light emitting material, the interaction between materialmolecules can be adequately controlled to make uniform the energy gapand interaction between adjacent molecules, whereby the drive voltagecan be more lowered.

Also, the compound represented by formula (VI) for use in the organicelectroluminescence device is excellent in chemical stability and lesscauses deterioration such as decomposition of the material duringdriving of the device, so that the organic electroluminescence devicecan be prevented from reduction in the efficiency or life due todecomposition of the material.

The compound represented by formula (VI) is described below.

In formula (VI), each of R₄, R₆, R₈, R₁₀ and X₄ to X₁₅ independentlyrepresents a hydrogen atom, an alkyl group or an aryl group.

The alkyl group represented by each of R₄, R₆, R₈, R₁₀ and X₄ to X₁₅ inthe formula (VI) may have as a substituent an adamantane structure or anaryl structure, and the number of carbon atoms in the alkyl group ispreferably from 1 to 70, far preferably from 1 to 50, further preferablyfrom 1 to 30, still further preferably from 1 to 10, especiallypreferably from 1 to 6. And the most preferable alkyl groups are linearalkyl groups having 2 to 6 carbon atoms.

Examples of the alkyl group represented by each of R₄, R₆, R₈, R₁₀ andX₄ to X₁₅ in the formula (VI) include an n-C₅₀H₁₀₁ group, an n-C₃₀H₆₁group, 3-(3,5,7-triphenyladamantane-1-yl)propyl group (number of carbonatoms: 31), a trityl group (number of carbon atoms: 19),3-(adamantane-1-yl)propyl group (number of carbon atoms: 13), 9-decalylgroup (number of carbon atoms: 10), a benzyl group (number of carbonatoms: 7), a cyclohexyl group (number of carbon atoms: 6), a n-hexylgroup (number of carbon atoms: 6), an n-pentyl group (number of carbonatoms: 5), an n-butyl group (number of carbon atoms: 4), an n-propylgroup (number of carbon atoms: 3), a cyclopropyl group (number of carbonatoms: 3), an ethyl group (number of carbon atoms: 2) and a methyl group(number of carbon atoms: 1).

The aryl group represented by each of R₄, R₆, R₈, R₁₀ and X₄ to X₁₅ inthe formula (VI) may have as a substituent an adamantane structure or analkyl structure, and the number of carbon atoms the aryl group has ispreferably from 6 to 30, far preferably from 6 to 20, further preferablyfrom 6 to 15, especially preferably from 6 to 10, the most preferably is6.

Examples of the aryl group represented by each of R₄, R₆, R₈, R₁₀ and X₄to X₁₅ in the formula (VI) include a 1-pyrenyl group (number of carbonatoms: 16), a 9-anthracenyl group (number of carbon atoms: 14), a1-naphthyl group (number of carbon atoms: 10), a 2-natphthyl group(number of carbon atom: 10), a p-t-butylphenyl group (number of carbonatoms: 10), a 2-m-xylyl group (number of carbon atoms: 8), a 5-m-xylylgroup (number of carbon atoms: 8), an o-tolyl group (number of carbonatoms: 7), a m-tolyl group (number of carbon atoms: 7), a p-tolyl group(number of carbon atoms: 7) and a phenyl group (number of carbon atoms:6).

Although each of R₄, R₆, R₈ and R₁₀ in the formula (VI) may be either ahydrogen atom, or an alkyl group, or an aryl group, from the viewpointthat high glass transition temperatures are preferable, it is preferablethat at least one of them is an aryl group, it is far preferable that atleast two of them are aryl groups, and it is particularly preferablethat 3 or 4 of them are aryl groups.

Although each of X₄ to X₁₅ in the formula (VI) may represent either ahydrogen atom, or an alkyl group, or an aryl group, it is preferablethat each stands for a hydrogen atom or an aryl group, especially ahydrogen atom.

The organic electroluminescence devices are made using a vacuumdeposition process or a solution coating process, and therefore, interms of vacuum deposition suitability and solubility, the molecularweight of the compounds represented by the formula (VI) in the inventionis preferably 2,000 or below, far preferably 1,200 or below, especially1,000 or below. Also, from the viewpoint of vacuum depositionsuitability, the molecular weight is preferably 250 or above, farpreferably 350 or above, particularly preferably 400 or above. This isbecause, when the compounds have too low molecular weight, their vaporpressure becomes low and change from a vapor phase to a solid phase doesnot occur, and it is therefore difficult for the compounds to formorganic layers.

The compound represented by the formula (VI) is preferably in solidphase at room temperature (25° C.), far preferably solid phase in arange from room temperature to 40° C., especially preferably solid phasein a range from room temperature to 60° C.

In the case of using the compound which, though represented by theformula (VI), is not in solid phase at room temperature, it is possibleto form a solid phase at ordinary temperatures by combining the compoundwith other substances.

Uses of the compound represented by the formula (VI) are not limited,and the compound may be incorporated into any of the organic layers. Thelayer into which the compound represented by the formula (VI) in theinvention is introduced is preferably a layer selected from a lightemitting layer, a hole injection layer, a hole transporting layer, anelectron transporting layer, an electron injection layer, an excitonblock layer and a charge blocking layer, or a combination of two or moreof these layers, far preferably a layer selected from the light emittinglayer, the hole injection layer, the hole transporting layer, theelectron transporting layer and the electron injection layer, or acombination of two or more of these layers, especially preferably alayer selected from the light emitting layer, the hole injection layerand the hole transporting layer, or a combination of at least two ofthese layers, the most preferably the light emitting layer.

When the compound represented by the formula (VI) is used in an organiclayer, its content is required to be limited so as not to inhibit chargetransportability, and therefore it is preferable from 0.1% to 70% bymass, far preferable from 0.1% to 30% by mass, especially preferablefrom 0.1% to 25% by mass.

When the compound represented by the formula (VI) is used in two or moreorganic layers, its content in each organic layer is preferably in therange specified above.

Only one kind of a compound represented by formula (VI) may be containedin any organic layer, or a plurality of kinds of compounds representedby formula (VI) may be contained in combination in an arbitrary ratio.

Specific examples of the hydrocarbon compound are illustrated below, butthe present invention is not limited thereto.

The compound represented by the formula (VI) can be synthesized byappropriately combining adamantane or haloadamantane with haloalkane oralkylmagnesium halide (Grignard reagent). For instance, it is possibleto provide coupling between haloadamantane and haloalkane by use ofindium (Reference 1). Alternatively, it is possible to converthaloalkane into an alkylcopper reagent and further to couple the reagentto Grignard reagent of an aromatic compound (Reference 2). Further, thecoupling of haloalkane can also be performed using an appropriatearylboric acid and a palladium catalyst (Reference 3).

-   Reference 1: Tetrahedron Lett. 39, 9557-9558 (1998)-   Reference 2: Tetrahedron Lett. 39, 2095-2096 (1998)-   Reference 3: J. Am. Chem. Soc. 124, 13662-13663 (2002)

The adamantane structure having an aryl group can be synthesized byappropriately combining adamantane or haloadamantane with thecorresponding arene or haloarene.

Additionally, even when defined substituents undergo changes undercertain synthesis conditions in those production methods or they areunsuitable for carrying out those methods, the intended compounds can beproduced with ease by adopting e.g. methods for protecting anddeprotecting functional groups (T. W. Greene, Protective Groups inOrganic Synthesis, John Wiley & Sons Inc. (1981)). Further, it is alsopossible to change the order of reaction steps, including a substituentintroduction step, as appropriate, if needed.

The thickness of the light emitting layer is not particularly limitedbut usually, the thickness is preferably from 1 to 500 nm, morepreferably from 5 to 200 nm, still more preferably from 10 to 100 nm.

—Hole Injection Layer, Hole Transporting Layer—

The hole injection layer and the hole transporting layer are a layerhaving a function of receiving a hole from the anode or anode side andtransporting it to the cathode side.

—Electron Injection Layer, Electron Transporting Layer—

The electron injection layer and the electron transporting layer are alayer having a function of receiving an electron from the cathode orcathode side and transporting it to the anode side.

As regards the hole injection layer, hole transporting layer, electroninjection layer and electron transporting layer, the matters describedin JP-A-2008-270736, paragraphs [0165] to [0167] can be applied to thepresent invention.

—Hole Blocking Layer—

The hole blocking layer is a layer having a function of blocking theholes transported from an anode side to the light emitting layer frompassing on through to the cathode side. In the invention, the holeblocking layer can be provided as an organic layer adjacent to the lightemitting layer in the cathode side.

Examples of an organic compound which forms the hole blocking layerinclude aluminum complexes such as aluminum (III)bis(2-methyl-8-quinolinato) 4-phenylphenolate (abbreviated to BAlq),triazole derivatives, and phenanthroline derivatives such as2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (abbreviated to BCP).

The thickness of the hole blocking layer is preferably from 1 nm to 500nm, far preferably from 5 nm to 200 nm, further preferably from 10 nm to100 nm.

The hole blocking layer may have either a single-layer structure made upof one or more than one material as recited above or a multiple-layerstructure made up of two or more layers which are identical or differentin composition.

—Electron Blocking Layer—

The electron blocking layer is a layer having a function of preventingthe electrons transported from the cathode side to the light emittinglayer from passing through to the anode side. In the invention, theelectron blocking layer can be provided as an organic layer adjacent tothe light emitting layer on the anode side.

As the examples of the compounds constituting the electron blockinglayer, for instance, the hole transporting materials described above canbe applied.

The thickness of the electron blocking layer is preferably from 1 nm to500 nm, more preferably from 5 nm to 200 nm, still more preferably from10 nm to 100 nm. The electron blocking layer may have a single layerstructure composed of one or more of the above materials or may be amultilayer structure composed of two or more layers having the samecomposition or different compositions.

<Protective Layer>

In the present invention, the entire organic EL device may be protectedby a protective layer.

As for the protective layer, the matters described in JP-A-2008-270736,paragraphs [0169] and [0170] can be applied to the present invention.

<Sealing Container>

The device of the present invention may be entirely sealed using asealing container.

As for the sealing container, the matters described in JP-A-2008-270736,paragraph[0171] can be applied to the present invention.

(Drive)

Luminescence of the organic electroluminescence device of the presentinvention can be obtained by applying a DC (if desired, an AC componentmay be contained) voltage (generally from 2 to 15 volts) or a DC currentbetween the anode and the cathode.

As for the driving method of the organic electroluminescence device ofthe present invention, the driving methods described, for example, inJP-A-2-148687, JP-A-6-301355, JP-A-5-29080, JP-A-7-134558,JP-A-8-234685, JP-A-8-241047, Japanese Patent 2784615, and U.S. Pat.Nos. 5,828,429 and 6,023,308 can be applied.

The present organic electroluminescence devices can be heightened inlight extraction efficiency by utilizing various publicly-knownimprovements. For instance, it is possible to improve light extractionefficiency and increase external quantum efficiency by working on thesubstrate's surface profile (e.g. forming a pattern of microscopicasperities on the substrate's surface), or by controlling refractiveindices of the substrate, the ITO layer and the organic layers, or bycontrolling thicknesses of the substrate, the ITO layer and the organiclayers, or so on.

The luminescence device of the present invention may be in a so-calledtop emission system of collecting light from the anode side.

The present organic EL devices may have resonator structure. Forinstance, each device has on a transparent substrate a multilayer filmminor made up of a plurality of laminated films that have differentrefractive indices, a transparent or translucent electrode, a lightemitting layer and a metal electrode which are superposed on top of eachother. Reflections of light produced in the light emitting layer occurrepeatedly between the multilayer film minor and the metal electrodewhich function as reflector plates, thereby producing resonance.

In another aspect, the transparent or translucent electrode and themetal electrode function as reflector plates, respectively, on thetransparent substrate, and reflections of light produced in the lightemitting layer occur repeatedly between the reflector plates, therebyproducing resonance.

In order to form a resonance structure, the optical distance determinedfrom effective refractive indices of the two reflector plates, andrefractive indices and thicknesses of each layers sandwiched between thetwo reflector plates are adjusted to have optimum values for achievingthe desired resonance wavelength. The calculating formula in the firstaspect case is described in JP-A-9-180883, and that in the second aspectcase is described in JP-A-2004-127795.

(Use of Luminescence Device of the Present Invention)

The present luminescence devices can be used suitably for light luminousapparatus, pixels, indication devices, displays, backlights,electrophotographic devices, illumination light sources, recording lightsources, exposure light sources, readout light sources, sign,billboards, interior decorations or optical communications, especiallypreferably for devices driven in a region of high-intensityluminescence, such as illumination apparatus and display apparatus.

Next the present light luminous apparatus is explained by reference toFIG. 2.

The present light luminous apparatus incorporates any one of the presentorganic electroluminescence devices.

FIG. 2 is a cross-sectional diagram schematically showing one example ofthe present light luminous apparatus.

The light luminous apparatus 20 in FIG. 2 includes a transparentsubstrate 2 (supporting substrate), an organic electroluminescencedevice 10, a sealing enclosure 16 and so on.

The organic electroluminescence device 10 is formed by stacking on thesubstrate 2 an anode 3 (first electrode), an organic layer 11 and acathode 9 (second electrode) in the order of mention. In addition, aprotective layer 12 is superposed on the cathode 9, and on theprotective layer 12 a sealing enclosure 16 is further provided via anadhesive layer 14. Incidentally, part of each of the electrodes 3 and 9,a diaphragm and an insulating layer are omitted in FIG. 2.

Herein, a light cure adhesive such as epoxy resin, or a thermosettingadhesive can be used for the adhesive layer 14. Alternatively, athermosetting adhesive sheet may be used as the adhesive layer 14.

The present light emission apparatus has no particular restrictions asto its uses, and specifically, it can be utilized e.g. as not onlyillumination apparatus but also display apparatus of a television set, apersonal computer, a mobile phone, an electronic paper or the like.

The illumination apparatus according to an embodiment of the presentinvention is described below by referring to FIG. 3.

The illumination apparatus 40 according to an embodiment of the presentinvention contains, as shown in FIG. 3, the above-described organicelectroluminescence device 10 and a light scattering member 30. Morespecifically, the illumination apparatus 40 is configured such that thesubstrate 2 of the organic electroluminescence device 10 and the lightscattering member 30 are in contact with each other.

The light scattering member 30 is not particularly limited as long as itcan scatter light, but in FIG. 3, a member obtained by dispersing fineparticles 32 in a transparent substrate 31 is used. Suitable examples ofthe transparent substrate 31 include a glass substrate, and suitableexamples of the fine particle 32 include a transparent resin fineparticle. As the glass substrate and the transparent resin fineparticle, a known product can be used for both. In such an illuminationapparatus 40, when light emitted from the organic electroluminescencedevice 10 is incident on the light incident surface 30A of thescattering member 30, the incident light is scattered by the lightscattering member and the scattered light is output as illuminatinglight from the light output surface 30B.

EXAMPLES

The present invention is described in greater detail below by referringto Examples, but the embodiment of the present invention is not limitedthereto.

Synthesis of Compound 2

Compound 2 was synthesized according to the following scheme.

In a nitrogen atmosphere, 2.1 equivalents of Ligand 1 and 1 equivalentof iridium chloride n-hydrate were reacted in a mixed solvent of2-ethoxyethanol/H₂O (=3:1) by refluxing at the boiling point for 5 hoursto obtain Chlorine Linked Complex 2. In 2-ethoxyethanol, Chlorine LinkedComplex 2 and 3 equivalents of acetylacetone were refluxed at theboiling point for 3 hours in the co-presence of sodium carbonate toobtain acac Complex 3. Subsequently, acac Complex 3 and 1.5 equivalentsof Ligand 1 were reacted in glycerol at 200° C., whereby the objectiveCompound 2 was synthesized.

Synthesis of Compound 157

Compound 157 was synthesized according to the following scheme.

From 1 to 1.2 equivalents of a base such as lithium diisopropylamide,potassium tert-butoxide and sodium hydride was added to anN,N-dimethylformamide solution of Compound (A) at 0° C. to roomtemperature, and the reaction was allowed to proceed at 0° C. to roomtemperature for about 30 minutes. Thereto, from 1.5 to 4 equivalents ofmethyl iodide was added and after monomethylation through reaction atroom temperature for about 30 minutes, from 1 to 1.2 equivalents of thebase described above and excess methyl iodide were again reacted underthe same conditions to obtain Dimethyl Substitution (B) in a yield of 70to 99%.

In the process of obtaining Compound (C) from Compound (B), Compound (B)as well as from 2 to 3 equivalents of sodium carbonate and from 0.05 to0.2 equivalents of tetrakis(triphenylphosphine)palladium(0) weredissolved in a toluene/ethanol/water mixed solvent or a1,2-dimethoxyethane/water mixed solvent, and the solution was heated toa temperature of 70° C. to heat-refluxing temperature and stirred for 2to 24 hours, whereby Compound (C) was synthesized.

In the process of obtaining Compound 157 from Compound (C), Compound (C)and from 1 to 1.5 equivalents of platinum chloride were dissolved inbenzonitrile, and the solution was heated to a temperature of 130° C. toheat-refluxing temperature (boiling point of benzonitrile: 191° C.) andstirred for 30 minutes to 4 hours, whereby the compound was synthesized.Compound 157 was purified by recrystallization using chloroform or ethylacetate, silica gel column chromatography, sublimation purification orthe like.

Incidentally, metal complexes represented by formulae (A1) to (A4) werealso synthesized by various techniques, for example, the methodsdescribed in U.S. Patent Application Publication 2007/0190359 and U.S.Patent Application Publication 2008/0297033. Furthermore, 11 and 12 canbe synthesized using the synthesis method described in JP-A-2009-102533,page 189, paragraphs 288 to 302.

Example 1 Example 1-1

A 0.5 mm-thickness 2.5 cm-square glass substrate having thereon ITO film(produced by GEOMATEC Corporation, surface resistance: 10 Ω/sq.) wasplaced in a cleaning vessel and subjected to ultrasonic cleaning in2-propanol and then to a UV-ozone treatment for 30 minutes. On thistransparent anode (ITO film), the following organic layers (organiccompound layers) were sequentially deposited by the vacuum depositionmethod.

Unless otherwise indicated, the vapor deposition rate in Examples of thepresent invention is 0.2 nm/sec. The vapor deposition rate was measuredusing a crystal oscillator. In the following, the film thickness is avalue as measured also by using a crystal oscillator.

After placing the cleaned ITO substrate in a vapor deposition apparatus,copper phthalocyanine was deposited to a thickness of 10 nm (firstlayer), and NPD (N,N′-di-α-naphthyl-N,N′-diphenyl)-benzidine) wasdeposited thereon to a thickness of 40 nm (second layer). Furthermore,H-1 and Compound A-1 of the present invention in a ratio of 95:5 (bymass) were deposited thereon to a thickness of 30 nm (third layer/lightemitting layer), and BAlq [aluminumbis-(2-methyl-8-quinolinato)-4-phenylphenolate] was deposited thereon toa thickness of 40 nm (fourth layer). Thereafter, lithium fluoride wasdeposited thereon to a thickness of 3 nm, and aluminum was furtherdeposited to a thickness of 60 nm. The obtained laminate was placed inan argon gas-purged glove box without exposing to the atmosphere andthen encapsulated using a stainless steel-made sealing can and anultraviolet curable adhesive (XNR5516HV, produced by Nagase-Ciba Ltd.)to produce the organic EL device of Example 1-1. A DC voltage wasapplied to the organic EL device to produce luminescence by using SourceMeasure Unit Model 2400 manufactured by Toyo Corp., as a result,luminescence derived from Compound A-1 of the present invention wasobtained.

Examples 1-2 to 1-5 and Comparative Examples 1-1 to 1-5

The devices of Examples 1-2 to 1-5 and Comparative Examples 1-1 to 1-5were produced in the same manner as in Example 1-1 except for changingthe materials used in Example 1-1 to the materials shown in Table 1. ADC voltage was applied to the organic EL device to produce luminescenceby using Source Measure Unit Model 2400 manufactured by Toyo Corp., as aresult, luminescence derived from respective light emitting materialswas obtained.

(Measurement of Drive Voltage)

Each of the organic electroluminescence devices of Examples 1-1 to 1-5and Comparative Examples 1-1 to 1-5 was set in an emissionspectrum-measuring system (ELS1500) manufactured by ShimadzuCorporation, and the applied voltage at a luminance of 100 cd/m² wasmeasured.

(Evaluation of Drive Durability)

Each of the organic electroluminescence devices of Examples 1-1 to 1-5and Comparative Examples 1-1 to 1-5 was set in OLED Test System ModelST-D manufactured by Tokyo System Development Co., Ltd. and driven underthe conditions of a constant-current mode and an initial luminance of1,000 cd/m², and the half-luminance time was measured.

(Evaluation of External Quantum Efficiency)

With respect to the organic electroluminescence devices of Examples 1-1to 1-5 and Comparative Examples 1-1 to 1-5, a DC voltage was applied tothe EL device to produce luminescence by using Source Measure Unit Model2400 manufactured by Toyo Corp., and the external quantum efficiency (%)was calculated from the frontal luminance at 100 cd/m²,

(Evaluation of Chromaticity)

A DC voltage was applied to obtain a luminance of 1,000 cd/m², and theemission spectrum was measured by an emission spectrum-measuring system(ELS1500) manufactured by Shimadzu Corporation to calculate thechromaticity (CIE chromaticity).

TABLE 1 External Half- Chromaticity Light Emitting Layer Drive QuantumLuminance after Light Voltage at Efficiency Time at Decrease to EmittingHost 100 cd/m² at 100 1000 cd/m² Initial Half Material Material (V)cd/m² (%) (relative value) Chromaticity Luminance Comparative B-1 H-17.6 13.8 100 (0.61, 0.38) (0.65, 0.33) Example 1-1 Comparative B-2 H-18.4 14.0 106 (0.65, 0.32) (0.68, 0.29) Example 1-2 Comparative B-3 H-17.3 11.6 76 (0.50, 0.49) (0.53, 0.45) Example 1-3 Comparative B-4 H-17.1 10.1 56 (0.39, 0.56) (0.46, 0.50) Example 1-4 Comparative B-5 H-17.3 14.6 82 (0.41, 0.57) (0.44, 0.52) Example 1-5 Example 1-1 A-1 H-17.4 14.4 125 (0.60, 0.36) (0.61, 0.36) Example 1-2 A-2 H-1 8.2 14.9 136(0.66, 0.33) (0.65, 0.32) Example 1-3 A-3 H-1 7.2 12.7 87 (0.51, 0.49)(0.51, 0.48) Example 1-4 A-4 H-1 7.0 10.9 71 (0.40, 0.56) (0.42, 0.55)Example 1-5 A-5 H-1 7.2 15.1 91 (0.42, 0.56) (0.42, 0.56)

It is seen that in Examples 1-1 to 1-5, the compound of the presentinvention is used as the light emitting material and therefore, thedevice exhibits high efficiency and a long half-luminance time and isexcellent in terms of durability as compared with Comparative Examples1-1 to 1-5. Also, the chromaticity shift is less caused at the devicedeterioration and the voltage is low.

Example 2 Example 2-1

The organic EL device of Example 2-1 was produced in the same manner asin Example 1-1 except that in Example 1-1, the film of the third layer(light emitting layer) was deposited (film thickness: 50 nm) by changingthe compositional ratio to H-1 and A-6 of 93:7 (by mass) from H-1 andA-1 of 95:5 (by mass). A DC voltage was applied to the organic EL deviceto produce luminescence by using Source Measure Unit Model 2400manufactured by Toyo Corp., as a result, luminescence derived from A-6was obtained.

Examples 2-2 to 2-4 and Comparative Examples 2-1 to 2-4

The devices of Examples 2-2 to 2-4 and Comparative Examples 2-1 to 2-4were produced in the same manner as in Example 2-1 except for changingthe materials used in Example 2-1 to the materials shown in Table 2. ADC voltage was applied to the organic EL device to produce luminescenceby using Source Measure Unit Model 2400 manufactured by Toyo Corp., as aresult, luminescence derived from respective light emitting materialswas obtained.

TABLE 2 External Half- Chromaticity Light Emitting Layer Drive QuantumLuminance after Light Voltage at Efficiency Time at Decrease to EmittingHost 100 cd/m² at 100 1000 cd/m² Initial Half Material Material (V)cd/m² (%) (relative value) Chromaticity Luminance Comparative B-6 H-18.1 13.3 100 (0.29, 0.64) (0.32, 0.60) Example 2-1 Comparative B-7 H-17.9 13.8 43 (0.25, 0.62) (0.33, 0.58) Example 2-2 Comparative B-8 H-18.5 11.8 66 (0.27, 0.61) (0.30, 0.66) Example 2-3 Comparative B-9 H-17.8 12.3 83 (0.28, 0.62) (0.33, 0.64) Example 2-4 Example 2-1 A-6 H-17.9 14.1 125 (0.28, 0.65) (0.29, 0.64) Example 2-2 A-7 H-1 7.7 14.6 63(0.24, 0.62) (0.25, 0.60) Example 2-3 A-8 H-1 8.4 12.3 79 (0.26, 0.60)(0.26, 0.62) Comparative A-9 H-1 7.7 12.6 89 (0.28, 0.63) (0.30, 0.64)Example 2-4

It is seen that in Examples 2-1 to 2-4, the compound of the presentinvention is used as the light emitting material and therefore, thedevice exhibits high efficiency and a long half-luminance time and isexcellent in terms of durability as compared with Comparative Examples2-1 to 2-4. Also, the chromaticity shift is less caused at the devicedeterioration and the voltage is low.

Example 3 Example 3-1

Compounds 33, 38 and 42 Described in JP-A-2008-210941

The organic EL device of Example 3-1 was produced in the same manner asin Example 1-1 except that in Example 1-1, the film of the third layer(light emitting layer) was deposited (film thickness: 50 nm) by changingthe compositional ratio to H-2 and A-10 of 93:7 (by mass) from H-1 andA-1 of 95:5 (by mass). A DC voltage was applied to the organic EL deviceto produce luminescence by using Source Measure Unit Model 2400manufactured by Toyo Corp., as a result, luminescence derived from A-10was obtained.

Examples 3-2 to 3-9 and Comparative Examples 3-1 to 3-8

The devices of Examples 3-2 to 3-9 and Comparative Examples 3-1 to 3-8were produced in the same manner as in Example 3-1 except for changingthe materials used in Example 3-1 to the materials shown in Table 3. ADC voltage was applied to the organic EL device to produce luminescenceby using Source Measure Unit Model 2400 manufactured by Toyo Corp., as aresult, luminescence derived from respective light emitting materialswas obtained.

TABLE 3 External Half- Chromaticity Light Emitting Layer Drive QuantumLuminance after Light Voltage at Efficiency Time at Decrease to EmittingHost 100 cd/m² at 100 1000 cd/m² Initial Half Material Material (V)cd/m² (%) (relative value) Chromaticity Luminance Comparative B-10 H-28.1 9.2 100 (0.17, 0.32) (0.19, 0.39) Example 3-1 Comparative B-11 H-38.8 7.8 43 (0.17, 0.29) (0.21, 0.35) Example 3-2 Comparative B-12 H-310.4 3.6 16 (0.17, 0.26) (0.20, 0.35) Example 3-3 Comparative B-13 H-27.9 8.7 83 (0.17, 0.28) (0.22, 0.35) Example 3-4 Comparative B-14 H-28.3 9.5 71 (0.17, 0.22) (0.21, 0.30) Example 3-5 Comparative C-10 H-28.3 8.8 49 (0.17, 0.33) (0.21, 0.41) Example 3-6 Comparative C-36 H-28.5 6.8 21 (0.17, 0.29) (0.21, 0.36) Example 3-7 Comparative C-37 H-28.6 6.9 22 (0.17, 0.29) (0.21, 0.36) Example 3-8 Example 3-1 A-10 H-28.0 9.7 110 (0.18, 0.33) (0.18, 0.36) Example 3-2 A-11 H-3 8.7 8.4 53(0.18, 0.30) (0.19, 0.32) Example 3-3 A-12 H-3 10.0 4.2 25 (0.18, 0.28)(0.18, 0.30) Example 3-4 A-13 H-2 7.6 9.4 94 (0.17, 0.28) (0.19, 0.31)Example 3-5 A-14 H-2 7.8 9.9 103 (0.17, 0.23) (0.18, 0.25) Example 3-6A-15 H-2 8.1 9.8 89 (0.17, 0.23) (0.17, 0.24) Example 3-7 A-35 H-2 7.89.0 108 (0.17, 0.33) (0.19, 0.35) Example 3-8 A-36 H-2 7.9 7.1 36 (0.17,0.29) (0.18, 0.31) Example 3-9 A-37 H-2 7.9 7.2 37 (0.17, 0.29) (0.18,0.31)

It is seen that in Examples 3-1 to 3-6, the compound of the presentinvention is used as the light emitting material and therefore, thedevice exhibits high efficiency and a long half-luminance time and isexcellent in terms of durability as compared with Comparative Examples3-1 to 3-5. Also, the chromaticity shift is less caused at the devicedeterioration and the voltage is low. Furthermore, in Examples 3-6 to3-9 using A-15, A-35, A-36 and A-37 of the present invention, the deviceis excellent in terms of durability (the half-luminance time is long),chromaticity shift at device deterioration, and low voltage as comparedwith Comparative Examples 3-6 to 3-8 using corresponding Compounds C-10,C-36 and C-37 described in JP-A-2008-210941.

Example 4 Example 4-1

The organic EL device of Example 4-1 was produced in the same manner asin Example 1-1 except that in Example 1-1, the film of the third layer(light emitting layer) was deposited (film thickness: 50 nm) by changingthe compositional ratio to H-2 and A-16 of 95:5 (by mass) from H-1 andA-1 of 95:5 (by mass). A DC voltage was applied to the organic EL deviceto produce luminescence by using Source Measure Unit Model 2400manufactured by Toyo Corp., as a result, luminescence derived from A-14was obtained.

Examples 4-2 to 4-9 and Comparative Examples 4-1 to 4-9

The devices of Examples 4-2 to 4-9 and Comparative Examples 4-1 to 4-9were produced in the same manner as in Example 4-1 except for changingthe materials used in Example 4-1 to the materials shown in Table 4. ADC voltage was applied to the organic EL device to produce luminescenceby using Source Measure Unit Model 2400 manufactured by Toyo Corp., as aresult, luminescence derived from respective light emitting materialswas obtained.

TABLE 4 External Half- Chromaticity Light Emitting Layer Drive QuantumLuminance after Light Voltage at Efficiency Time at Decrease to EmittingHost 100 cd/m² at 100 1000 cd/m² Initial Half Material Material (V)cd/m² (%) (relative value) Chromaticity Luminance Comparative B-16 H-28.6 9.9 100 (0.29, 0.63) (0.34, 0.63) Example 4-1 Comparative B-17 H-39.8 7.9 59 (0.17, 0.29) (0.24, 0.35) Example 4-2 Comparative B-18 H-39.4 8.5 57 (0.17, 0.29) (0.23, 0.35) Example 4-3 Comparative B-19 H-29.9 7.7 52 (0.20, 0.29) (0.26, 0.35) Example 4-4 Comparative B-20 H-28.9 8.2 55 (0.21, 0.30) (0.26, 0.34) Example 4-5 Comparative B-21 H-29.0 7.1 44 (0.24, 0.66) (0.29, 0.60) Example 4-6 Comparative B-22 H-29.6 7.2 58 (0.23, 0.37) (0.27, 0.42) Example 4-7 Comparative B-23 H-29.9 6.8 28 (0.16, 0.24) (0.22, 0.30) Example 4-8 Comparative B-24 H-38.9 7.8 46 (0.20, 0.30) (0.26, 0.35) Example 4-9 Example 4-1 A-16 H-27.9 11.3 118 (0.29, 0.60) (0.29, 0.61) Example 4-2 A-17 H-3 8.9 8.0 77(0.16, 0.28) (0.19, 0.31) Example 4-3 A-18 H-3 9.3 9.2 69 (0.18, 0.30)(0.18, 0.32) Example 4-4 A-19 H-2 7.6 9.2 61 (0.21, 0.30) (0.22, 0.31)Example 4-5 A-20 H-2 8.2 9.7 66 (0.22, 0.30) (0.23, 0.33) Example 4-6A-21 H-2 8.1 9.7 55 (0.24, 0.65) (0.25, 0.63) Example 4-7 A-22 H-2 9.08.1 70 (0.23, 0.36) (0.25, 0.38) Example 4-8 A-23 H-2 9.5 7.4 38 (0.16,0.24) (0.18, 0.26) Example 4-9 A-24 H-3 8.4 8.3 56 (0.19, 0.29) (0.21,0.32)

It is seen that in Examples 4-1 to 4-9, the compound of the presentinvention is used as the light emitting material and therefore, thedevice exhibits high efficiency and a long half-luminance time and isexcellent in terms of durability as compared with Comparative Examples4-1 to 4-9. Also, the chromaticity shift is less caused at the devicedeterioration and the voltage is low.

Example 5 Example 5-1

A 0.5 mm-thick 2.5 cm-square glass substrate having thereon ITO film(produced by GEOMATEC Corporation, surface resistance: 10 Ω/sq.) wasplaced in a cleaning vessel and subjected to ultrasonic cleaning in2-propanol and then to a UV-ozone treatment for 30 minutes. On thissubstrate, a solution obtained by dilutingpoly(3,4-ethylenedioxythiophene)-polystyrene sulfonate (PEDOT/PSS) to70% with pure water was coated by means of a spin coater to provide ahole transporting layer of 50 nm in thickness, and a methylene chloridesolution having dissolved therein H-1 and A-1 in a ratio of 98/2 (bymass) was further coated by means of a spin coater to obtain a lightemitting layer of 30 nm in thickness. Thereafter, BAlq [aluminumbis-(2-methyl-8-quinolinato)-4-phenylphenolate] was deposited thereon toa thickness of 40 nm (fourth layer). On this organic compound layer,lithium fluoride of 0.5 nm as a cathode buffer layer and aluminum of 150nm as a cathode were deposited in a vapor deposition apparatus. Theobtained laminate was placed in an argon gas-purged glove box withoutexposing to the atmosphere and then encapsulated using a stainlesssteel-made sealing can and an ultraviolet curable adhesive (XNR5516HV,produced by Nagase-Ciba Ltd.) to produce the organic EL device ofExample 5-1. A DC voltage was applied to the organic EL device toproduce luminescence by using Source Measure Unit Model 2400manufactured by Toyo Corp., as a result, luminescence derived fromCompound A-1 of the present invention was obtained.

Examples 5-2 to 5-3 and Comparative Examples 5-1 to 5-3

The devices of Examples 5-2 to 5-3 and Comparative Examples 5-1 to 5-3were produced in the same manner as in Example 5-1 except for changingthe materials used in Example 5-1 to the materials shown in Table 5. ADC voltage was applied to the organic EL device to produce luminescenceby using Source Measure Unit Model 2400 manufactured by Toyo Corp., as aresult, luminescence derived from respective light emitting materialswas obtained.

TABLE 5 External Half- Chromaticity Light Emitting Layer Drive QuantumLuminance after Light Voltage at Efficiency Time at Decrease to EmittingHost 100 cd/m² at 100 1000 cd/m² Initial Half Material Material (V)cd/m² (%) (relative value) Chromaticity Luminance Comparative B-1 H-111.2 8.3 100 (0.61, 0.38) (0.66, 0.31) Example 5-1 Comparative B-3 H-111.8 6.7 66 (0.49, 0.49) (0.53, 0.45) Example 5-2 Comparative B-5 H-111.1 9.2 62 (0.41, 0.57) (0.44, 0.52) Example 5-3 Example 5-1 A-1 H-110.5 9.0 128 (0.60, 0.37) (0.61, 0.35) Example 5-2 A-3 H-1 10.4 7.8 85(0.51, 0.49) (0.52, 0.47) Example 5-3 A-5 H-1 10.2 10.4 87 (0.42, 0.56)(0.41, 0.55)

It is seen that in Examples 5-1 to 5-3, the compound of the presentinvention is used as the light emitting material and therefore, thedevice exhibits high efficiency and a long half-luminance time and isexcellent in terms of durability as compared with Comparative Examples5-1 to 5-3. Also, the chromaticity shift is less caused at the devicedeterioration and the voltage is low.

Example 6 Example 6-1

The organic EL device of Example 6-1 was produced in the same manner asin Example 5-1 except that in Example 5-1, the solution of the thirdlayer (light emitting layer) was coated (film thickness: 50 nm) bychanging the compositional ratio to H-1 and A-6 of 96:4 (by mass) fromH-1 and A-1 of 98:2 (by mass). A DC voltage was applied to the organicEL device to produce luminescence by using Source Measure Unit Model2400 manufactured by Toyo Corp., as a result, luminescence derived fromA-6 was obtained.

Example 6-2 and Comparative Examples 6-1 and 6-2

The devices of Example 6-2 and Comparative Examples 6-1 and 6-2 wereproduced in the same manner as in Example 6-1 except for changing thematerials used in Example 6-1 to the materials shown in Table 6. A DCvoltage was applied to the organic EL device to produce luminescence byusing Source Measure Unit Model 2400 manufactured by Toyo Corp., as aresult, luminescence derived from respective light emitting materialswas obtained.

TABLE 6 External Half- Chromaticity Light Emitting Layer Drive QuantumLuminance after Light Voltage at Efficiency Time at Decrease to EmittingHost 100 cd/m² at 100 1000 cd/m² Initial Half Material Material (V)cd/m² (%) (relative value) Chromaticity Luminance Comparative B-6 H-111.6 8.3 100 (0.29, 0.64) (0.33, 0.59) Example 6-1 Comparative B-8 H-111.9 6.8 71 (0.27, 0.61) (0.32, 0.68) Example 6-2 Example 6-1 A-6 H-110.7 9.0 115 (0.27, 0.65) (0.29, 0.64) Example 6-2 A-8 H-1 11.2 7.5 80(0.26, 0.60) (0.28, 0.64)

It is seen that in Examples 6-1 and 6-2, the compound of the presentinvention is used as the light emitting material and therefore, thedevice exhibits high efficiency and a long half-luminance time and isexcellent in terms of durability as compared with Comparative Examples6-1 and 6-2. Also, the chromaticity shift is less caused at the devicedeterioration and the voltage is low.

Example 7 Example 7-1

The organic EL device of Example 7-1 was produced in the same manner asin Example 5-1 except that in Example 5-1, the solution of the thirdlayer (light emitting layer) was coated (film thickness: 50 nm) bychanging the compositional ratio to H-4 and A-10 of 96:4 (by mass) fromH-1 and A-1 of 98:2 (by mass). A DC voltage was applied to the organicEL device to produce luminescence by using Source Measure Unit Model2400 manufactured by Toyo Corp., as a result, luminescence derived fromA-6 was obtained.

Example 7-2 and Comparative Examples 7-1 and 7-2

The devices of Example 7-2 and Comparative Examples 7-1 and 7-2 wereproduced in the same manner as in Example 7-1 except for changing thematerials used in Example 7-1 to the materials shown in Table 7. A DCvoltage was applied to the organic EL device to produce luminescence byusing Source Measure Unit Model 2400 manufactured by Toyo Corp., as aresult, luminescence derived from respective light emitting materialswas obtained.

TABLE 7 External Half- Chromaticity Light Emitting Layer Drive QuantumLuminance after Light Voltage at Efficiency Time at Decrease to EmittingHost 100 cd/m² at 100 1000 cd/m² Initial Half Material Material (V)cd/m² (%) (relative value) Chromaticity Luminance Comparative B-10 H-414.1 5.8 100 (0.17, 0.32) (0.20, 0.40) Example 7-1 Comparative B-14 H-413.9 6.1 75 (0.17, 0.22) (0.21, 0.30) Example 7-2 Example 7-1 A-10 H-413.6 6.7 113 (0.18, 0.33) (0.19, 0.34) Example 7-2 A-14 H-4 13.4 6.9 94(0.17, 0.22) (0.18, 0.24)

It is seen that in Examples 7-1 and 7-2, the compound of the presentinvention is used as the light emitting material and therefore, thedevice exhibits high efficiency and a long half-luminance time and isexcellent in terms of durability as compared with Comparative Examples7-1 and 7-2. Also, the chromaticity shift is less caused at the devicedeterioration and the voltage is low.

Example 8 Example 8-1

The organic EL device of Example 8-1 was produced in the same manner asin Example 5-1 except that in Example 5-1, the solution of the thirdlayer (light emitting layer) was coated (film thickness: 50 nm) bychanging the compositional ratio to H-4 and A-16 of 96:4 (by mass) fromH-1 and A-1 of 98:2 (by mass). A DC voltage was applied to the organicEL device to produce luminescence by using Source Measure Unit Model2400 manufactured by Toyo Corp., as a result, luminescence derived fromA-16 was obtained.

Examples 8-2 to 8-5 and Comparative Examples 8-1 to 8-5

The devices of Examples 8-2 to 8-5 and Comparative Examples 8-1 to 8-5were produced in the same manner as in Example 8-1 except for changingthe materials used in Example 8-1 to the materials shown in Table 8. ADC voltage was applied to the organic EL device to produce luminescenceby using Source Measure Unit Model 2400 manufactured by Toyo Corp., as aresult, luminescence derived from respective light emitting materialswas obtained.

TABLE 8 External Half- Chromaticity Light Emitting Layer Drive QuantumLuminance after Light Voltage at Efficiency Time at Decrease to EmittingHost 100 cd/m² at 100 1000 cd/m² Initial Half Material Material (V)cd/m² (%) (relative value) Chromaticity Luminance Comparative B-15 H-413.3 6.1 100 (0.29, 0.63) (0.31, 0.63) Example 8-1 Comparative B-16 H-414.5 4.7 64 (0.18, 0.30) (0.20, 0.34) Example 8-2 Comparative B-17 H-414.1 5.7 61 (0.18, 0.30) (0.20, 0.33) Example 8-3 Comparative B-20 H-413.8 5.3 47 (0.24, 0.66) (0.27, 0.62) Example 8-4 Comparative B-22 H-415.5 4.3 32 (0.16, 0.24) (0.23, 0.32) Example 8-5 Example 8-1 A-15 H-412.7 6.9 116 (0.29, 0.60) (0.30, 0.62) Example 8-2 A-16 H-4 13.6 5.6 79(0.17, 0.29) (0.19, 0.32) Example 8-3 A-17 H-4 13.7 6.6 73 (0.19, 0.30)(0.20, 0.32) Example 8-4 A-20 H-4 13.0 6.3 56 (0.24, 0.65) (0.26, 0.64)Example 8-5 A-22 H-4 14.9 5.0 43 (0.16, 0.24) (0.19, 0.27)

It is seen that in Examples 8-1 to 8-5, the compound of the presentinvention is used as the light emitting material and therefore, thedevice exhibits high efficiency and a long half-luminance time and isexcellent in terms of durability as compared with Comparative Examples8-1 to 8-5. Also, the chromaticity shift is less caused at the devicedeterioration and the voltage is low.

Example 9 Example 9-1

The organic EL device of Example 9-1 was produced in the same manner asin Example 1-1 except that in Example 1-1, the film of the third layer(light emitting layer) was deposited (film thickness: 50 nm) by changingthe compositional ratio to H-1 and A-6 of 93:7 (by mass) from H-1 andA-1 of 98:2 (by mass). A DC voltage was applied to the organic EL deviceto produce luminescence by using Source Measure Unit Model 2400manufactured by Toyo Corp., as a result, luminescence derived from A-6was obtained.

Examples 9-2 to 9-6 and Comparative Example 9-1

The devices of Examples 9-2 to 9-6 and Comparative Example 9-1 wereproduced in the same manner as in Example 9-1 except for changing thematerials used in Example 9-1 to the materials shown in Table 9. A DCvoltage was applied to the organic EL device to produce luminescence byusing Source Measure Unit Model 2400 manufactured by Toyo Corp., as aresult, luminescence derived from respective light emitting materialswas obtained.

TABLE 9 External Half- Chromaticity Light Emitting Layer Drive QuantumLuminance after Light Voltage at Efficiency Time at Decrease to EmittingHost 100 cd/m² at 100 1000 cd/m² Initial Half Material Material (V)cd/m² (%) (relative value) Chromaticity Luminance Comparative B-6 H-18.1 13.3 100 (0.29, 0.64) (0.32, 0.60) Example 9-1 Example 9-1 A-6 H-17.9 14.1 125 (0.28, 0.65) (0.29, 0.64) Example 9-2 A-25 H-1 7.8 14.0 121(0.29, 0.64) (0.30, 0.63) Example 9-3 A-26 H-1 7.7 13.8 109 (0.29, 0.64)(0.31, 0.62) Example 9-4 A-27 H-1 8.0 13.8 119 (0.30, 0.62) (0.31, 0.63)Example 9-5 A-28 H-1 7.9 14.0 121 (0.31, 0.63) (0.31, 0.62) Example 9-6A-29 H-1 7.9 13.9 119 (0.29, 0.64) (0.30, 0.63)

It is seen that in Examples 9-1 to 9-6, the compound of the presentinvention is used as the light emitting material and therefore, althoughthe degree of effect differs according to the number of partialstructures and the substitution position, the device exhibits highefficiency and a long half-luminance time and is excellent in terms ofdurability as compared with Comparative Example 9-1. Also, thechromaticity shift is less caused at the device deterioration and thevoltage is low.

Example 10 Example 10-1

The organic EL device of Example 10-1 was produced in the same manner asin Example 1-1 except that in Example 1-1, the film of the third layer(light emitting layer) was deposited (film thickness: 50 nm) by changingthe compositional ratio to H-2 and A-14 of 90:10 (by mass) from H-1 andA-1 of 95:5 (by mass). A DC voltage was applied to the organic EL deviceto produce luminescence by using Source Measure Unit Model 2400manufactured by Toyo Corp., as a result, luminescence derived from A-14was obtained.

Examples 10-2 to 10-4 and Comparative Example 10-1

The devices of Examples 10-2 to 10-4 and Comparative Example 10-1 wereproduced in the same manner as in Example 10-1 except for changing thematerials used in Example 10-1 to the materials shown in Table 10. A DCvoltage was applied to the organic EL device to produce luminescence byusing Source Measure Unit Model 2400 manufactured by Toyo Corp., as aresult, luminescence derived from respective light emitting materialswas obtained.

TABLE 10 External Half- Chromaticity Light Emitting Layer Drive QuantumLuminance after Light Voltage at Efficiency Time at Decrease to EmittingHost 100 cd/m² at 100 1000 cd/m² Initial Half Material Material (V)cd/m² (%) (relative value) Chromaticity Luminance Comparative B-14 H-28.3 9.5 100 (0.17, 0.22) (0.21, 0.30) Example 10-1 Example 10-1 A-14 H-27.8 10.2 143 (0.17, 0.23) (0.18, 0.24) Example 10-2 A-30 H-2 7.9 10.1145 (0.17, 0.22) (0.17, 0.23) Example 10-3 A-31 H-2 8.1 9.7 127 (0.17,0.23) (0.19, 0.26) Example 10-4 A-32 H-2 8.1 9.7 125 (0.17, 0.23) (0.19,0.26)

It is seen that in Examples 10-1 to 10-4, the compound of the presentinvention is used as the light emitting material and therefore, althoughthe degree of effect differs according to the number of partialstructures and the substitution position, the device exhibits highefficiency and a long half-luminance time and is excellent in terms ofdurability as compared with Comparative Example 10-1. Also, thechromaticity shift is less caused at the device deterioration and thevoltage is low.

Example 11 Example 11-1

The organic EL device of Example 11-1 was produced in the same manner asin Example 1-1 except that in Example 1-1, the film of the third layer(light emitting layer) was deposited (film thickness: 50 nm) by changingthe compositional ratio to H-2 and A-17 of 90:10 (by mass) from H-1 andA-1 of 95:5 (by mass). A DC voltage was applied to the organic EL deviceto produce luminescence by using Source Measure Unit Model 2400manufactured by Toyo Corp., as a result, luminescence derived from A-17was obtained.

Examples 11-2 and 11-3 and Comparative Example 11-1

The devices of Examples 11-2 and 11-3 and Comparative Example 11-1 wereproduced in the same manner as in Example 11-1 except for changing thematerials used in Example 11-1 to the materials shown in Table 11. A DCvoltage was applied to the organic EL device to produce luminescence byusing Source Measure Unit Model 2400 manufactured by Toyo Corp., as aresult, luminescence derived from respective light emitting materialswas obtained.

TABLE 11 External Half- Chromaticity Light Emitting Layer Drive QuantumLuminance after Light Voltage at Efficiency Time at Decrease to EmittingHost 100 cd/m² at 100 1000 cd/m² Initial Half Material Material (V)cd/m² (%) (relative value) Chromaticity Luminance Comparative B-17 H-39.8 7.9 100 (0.17, 0.29) (0.24, 0.35) Example 11-1 Example 11-1 A-17 H-38.8 8.6 126 (0.16, 0.28) (0.20, 0.33) Example 11-2 A-33 H-3 9.0 8.5 121(0.16, 0.28) (0.20, 0.32) Example 11-3 A-34 H-3 8.9 8.6 125 (0.16, 0.29)(0.20, 0.32)

It is seen that in Examples 11-1 to 11-3, the compound of the presentinvention is used as the light emitting material and therefore, thedevice exhibits high efficiency and a long half-luminance time and isexcellent in terms of durability as compared with Comparative Example11-1. Also, the chromaticity shift is less caused at the devicedeterioration and the voltage is low.

Example 12 Example 12-1

A 100 μm-thick 2.5 cm-square glass substrate having thereon indium tinoxide (ITO) film (produced by GEOMATEC Corporation, surface resistance:10 Ω/sq.) was placed in a cleaning vessel and subjected to ultrasoniccleaning in 2-propanol and then to a UV-ozone treatment for 30 minutes.On this transparent anode (ITO film), the following organic compoundlayers were sequentially deposited by the vacuum deposition method.

First layer: CuPc (copper phthalocyanine), thickness: 120 nm

Second layer: NPD (N,N-di-α-naphthyl-N,N′-diphenyl)-benzidine,thickness: 7 nm

Third layer: CBP (4,4′-di(9-carbazoyl)biphenyl), thickness: 3 nm

Fourth layer (light emitting layer): dopant (9 mass %), mCBP (91 mass%), thickness: 30 nm

Fifth layer: first electron transporting material (Ba1q), thickness: 30nm

On this layer, lithium fluoride of 1 nm and metal aluminum of 100 nmwere deposited in this order to form a cathode.

The obtained laminate was placed in an argon gas-purged glove boxwithout exposing to the atmosphere and then encapsulated using astainless steel-made sealing can and an ultraviolet curable adhesive(XNR5516HV, produced by Nagase-Ciba Ltd.) to obtain the organic ELdevice of Example 12-1.

Examples 12-2 to 12-16 and Comparative Examples 12-1 to 12-13

The devices of Examples 12-2 to 12-16 and Comparative Examples 12-1 to12-13 were produced in the same manner as in Example 12-1 except forchanging the light emitting material of the device as shown in Table 12below.

(Performance Evaluation of Organic Electroluminescence Device)

A DC voltage was applied to the organic EL device to produceluminescence by using Source Measure Unit Model 2400 manufactured byToyo Corp., as a result, luminescence derived from the light emittingmaterial used was obtained. The results are shown together in Table 12.

TABLE 12 External Half- Chromaticity Drive Quantum Luminance after LightVoltage Efficiency Time at Decrease to Emitting at 100 at 100 1000 cd/m²Initial Half Material cd/m² (V) cd/m² (%) (relative value) ChromaticityLuminance Comparative ref 1 9.2 3.1 100 (0.17, 0.29) (0.23, 0.37)Example 12-1 Example 12-1 I-1 9.0 5.1 115 (0.17, 0.28) (0.20, 0.35)Comparative ref 2 9.3 8.8 85 (0.17, 0.29) (0.23, 0.37) Example 12-2Comparative ref 3 9.6 7.0 120 (0.17, 0.28) (0.21, 0.36) Example 12-3Example 12-2 I-2 9.2 9.9 135 (0.17, 0.28) (0.19, 0.32) Example 12-3 I-39.3 9.8 125 (0.17, 0.30) (0.20, 0.33) Comparative ref 4 9.5 6.6 128(0.17, 0.29) (0.22, 0.35) Example 12-4 Example 12-4 I-4 9.2 7.2 143(0.17, 0.29) (0.20, 0.32) Comparative ref 5 9.5 7.0 122 (0.17, 0.30)(0.23, 0.34) Example 12-5 Example 12-5 I-5 9.0 7.8 139 (0.17, 0.29)(0.20, 0.32) Example 12-6 I-6 9.0 7.7 138 (0.17, 0.29) (0.20, 0.33)Example 12-7 I-7 9.2 7.6 135 (0.17, 0.30) (0.19, 0.32) Example 12-8 I-89.2 7.6 137 (0.17, 0.30) (0.19, 0.31) Comparative ref 6 9.0 8.0 88(0.17, 0.30) (0.23, 0.39) Example 12-6 Example 12-9 I-9 8.8 8.8 105(0.18, 0.31) (0.22, 0.36) Comparative ref 7 9.3 6.1 95 (0.21, 0.34)(0.26, 0.39) Example 12-7 Example 12-10 I-10 9.0 6.7 107 (0.21, 0.33)(0.25, 0.35) Comparative ref 8 9.4 6.0 92 (0.24, 0.36) (0.28, 0.42)Example 12-8 Example 12-11 I-11 9.2 6.9 106 (0.23, 0.35) (0.26, 0.39)Comparative ref 9 9.5 5.8 60 (0.26, 0.54) (0.29, 0.59) Example 12-9Example 12-12 I-12 9.3 6.5 70 (0.26, 0.54) (0.27, 0.56) Comparative ref10 9.3 6.1 130 (0.19, 0.28) (0.24, 0.33) Example 12-10 Example 12-13I-13 9.1 6.7 142 (0.19, 0.28) (0.21, 0.30) Comparative ref 11 9.2 6.7135 (0.19, 0.28) (0.25, 0.32) Example 12-11 Example 12-14 I-14 9.0 7.5147 (0.18, 0.28) (0.20, 0.31) Comparative ref 12 9.5 6.6 75 (0.21, 0.34)(0.25, 0.38) Example 12-12 Example 12-15 I-15 9.2 7.3 88 (0.20, 0.34)(0.23, 0.36) Comparative ref-13 9.2 7.0 90 (0.17, 0.30) (0.24, 0.36)Example 12-13 Example 12-16 I-16 9.0 7.8 105 (0.17, 0.29) (0.20, 0.32)

It is seen that in Examples 12-1 to 12-16, the compound of the presentinvention is used as the light emitting material and therefore, bothhigh efficiency and a long half-luminance time are satisfied and thedevice is excellent in terms of durability as compared with ComparativeExamples 12-1 to 12-13 using corresponding compounds described in U.S.Patent Application Publication 2008-297033. Also, the chromaticity shiftis less caused at the device deterioration and the voltage is low.

INDUSTRIAL APPLICABILITY

According to the present invention, an organic electroluminescencedevice having high luminous efficiency (for example, external quantumefficiency), high durability and a long life of the device and causinglittle chromaticity shift after device deterioration can be provided.

This application is based on Japanese patent application No. 2009-201150filed on Aug. 31, 2009, the entire content of which is herebyincorporated by reference, the same as if set forth at length.

REFERENCE SIGNS LIST

-   2 Substrate-   3 Anode-   4 Hole injection layer-   5 Hole transporting layer-   6 Light emitting layer-   7 Hole blocking layer-   8 Electron transporting layer-   9 Cathode-   10 Organic electroluminescence device (organic EL device)-   11 Organic layer-   12 Protective layer-   14 Adhesive layer-   16 Sealing container-   20 Light emission apparatus-   30 Light scattering member-   30A Light incident surface-   30B Light output surface-   32 Fine particle-   40 Illumination apparatus

The invention claimed is:
 1. An organic electroluminescence devicecomprising, on a substrate: a pair of electrodes; and at least oneorganic layer between said electrodes, the organic layer containing alight emitting layer, wherein the light emitting layer contains as alight emitting material a metal complex of formula (2), formula (14), ora metal complex comprising a monoanionic bidentate ligand represented byformula (A1-1), having a group represented by the following formula (I):

wherein R₁ represents an alkyl group; each of R₂ and R₃ independentlyrepresents a hydrogen atom or an alkyl group; n^(s) represents aninteger of 0 to 6; and Z represents a saturated 5-, 7-, or 8-memberedring;

formula (2); wherein M²¹ represents a metal belonging to Groups 8 to 11in the periodic table of elements; A²¹ to A²³ each independentlyrepresent a nitrogen atom or a carbon atom; Z²¹ represents a quinolinering, an isoquinoline ring, a benzoxazole ring, a pyridine ring, or apyrazole ring; Z²² represents a benzene ring, a pyrazole ring, apyridine ring, a benzoxazole ring, or a thiophene ring; L²² and L²³ eachrepresent a carbon atom, a nitrogen atom, or an oxygen atom and formtogether with E²¹ a bidentate ligand of a phenylpyridine, apyridylpyridine, a picolinic acid, or an acetylacetone; wherein thebidentate ligand may be further substituted; k represents an integer of1 to 3; l represents an integer of 0 to 2; k+l is 2 or 3; S²¹ and S²²each independently represent the group represented by formula (I); n andm each represent an integer of 0 to 4; n+m is an integer of 1 to 4; andS²¹s or S²²s may be the same as or different from every other S²¹ orS²², respectively; and Z²¹ and Z²² may further comprise an alkyl group,a fluorine atom, and a cyano group;

formula (14); wherein A¹⁴¹ to A¹⁴⁶ each independently represent anitrogen atom or a carbon atom; Z¹⁴¹ and Z¹⁴² each independentlyrepresent an isoquinoline ring, a benzoxazole ring, a pyridine ring, animidazole ring, or a pyrazole ring; Z¹⁴³ and Z¹⁴⁴ each independentlyrepresent an isoquinoline ring, a benzoxazole ring, a benzene ring, apyridine ring, an imidazole ring, or a pyrazole ring; E¹⁴¹ represents adivalent linking group represented by —C(R¹)(R²)—, wherein R¹ and R²represent an alkyl group; S¹⁴¹ to S¹⁴⁴ each independently represent thegroup represented by formula (I); Z¹⁴³ and Z¹⁴⁴ may further comprise analkyl group, a fluorine atom, a methoxy group, an aryl group, or a cyanogroup; n, m, k and l represents an integer of 0 to 2; n+m+k+l is aninteger of 1 to 2; and S¹⁴¹s, S¹⁴²s, S¹⁴³s, S¹⁴⁴s may be the same as ordifferent from every other S¹⁴¹, S¹⁴², S¹⁴³ or S¹⁴⁴, respectively;

formula (A1-1) wherein E_(1f) to E_(1q) each independently represent acarbon atom or a heteroatom; R_(1a) to R_(1i) each independentlyrepresent a hydrogen atom, an alkyl group, a cycloalkyl group, an arylgroup, a cyano group, a fluorine atom, or a group represented by formula(I), wherein at least one of R_(1a) to R_(1i) represents a grouprepresented by formula (I); the framework represented by formula (A1-1)has a structure with 18 π-electrons in total; and the metal complexcomprising the monoanionic bidentate ligand (A1-1) comprises a metalhaving an atomic weight of 40 or more.
 2. The organicelectroluminescence device as claimed in claim 1, wherein in formula(I), n^(s) represents an integer of 1 to
 3. 3. The organicelectroluminescence device as claimed in claim 1, wherein in formula(I), n^(s) is
 1. 4. The organic electroluminescence device as claimed inclaim 1, wherein in formula (I), each of R₂ and R₃ represents a hydrogenatom.
 5. The organic electroluminescence device as claimed in claim 1,wherein in formula (I), Z represents a cyclopentyl group.
 6. The organicelectroluminescence device as claimed in claim 1, wherein the metalcomplex represented by formula (2) is represented by the followingformula (4):

wherein M⁴¹ represents a metal belonging to Groups 8 to 11 in theperiodic table of elements; each of R⁴³ to R⁴⁶ independently representsa hydrogen atom or a substituent; each of B⁴¹ to B⁴⁴ independentlyrepresents a nitrogen atom or C—R⁴⁷, wherein the number of nitrogenatoms of B⁴¹ to B⁴⁴ is 0 or 1, R⁴⁷ represents a hydrogen atom or asubstituent; each R⁴⁷ may be the same as or different from every otherR⁴⁷; L⁴², L⁴³, and E⁴¹ have the same meaning as L²², L²³, and E²¹,respectively; k represents an integer of 1 to 3; l represents an integerof 0 to 2; k+l is 2 or 3; each of S⁴¹ and S⁴² independently represents agroup represented by formula (I); each of n and m represents an integerof 0 to 4; n+m is an integer of 1 to 4; and each S⁴¹ or S⁴² may be thesame as or different from every other S⁴¹ or S⁴².
 7. The organicelectroluminescence device as claimed in claim 6, wherein the metalcomplex represented by formula (4) is represented by the followingformula (5):

wherein M⁵¹ represents a metal belonging to Groups 8 to 11 in theperiodic table of elements; each of R⁵³ to R⁵⁹ and R⁵¹⁰ independentlyrepresents a hydrogen atom or a substituent; L⁵², L⁵³, and E⁵¹ have thesame meaning as L²², L²³, and E²¹, respectively; k represents an integerof 1 to 3; l represents an integer of 0 to 2; k+l is 2 or 3; each of S⁵¹and S⁵² independently represents a group represented by formula (I);each of n and m represents an integer of 0 to 4; n+m is an integer of 1to 4; and each S⁵¹ or S⁵² may be the same as or different from everyother S⁵¹ or S⁵².
 8. The organic electroluminescence device as claimedin claim 1, wherein the metal complex represented by formula (2) isrepresented by the following formula (7):

wherein M⁷¹ represents a metal belonging to Groups 8 to 11 in theperiodic table of elements; each of R⁷³ to R⁷⁶ independently representsa hydrogen atom or a substituent; each of A⁷¹ and A⁷² independentlyrepresents a nitrogen atom or a carbon atom; each of D⁷¹ to D⁷³independently represents an atom selected from carbon, nitrogen, oxygen,and sulfur; the bond between atoms in the 5-membered ring formed by D⁷¹to D⁷³, A⁷¹ and A⁷² represents a single bond or a double bond, providedthat the 5-membered ring formed by D⁷¹ to D⁷³, A⁷¹ and A⁷² is a pyrazolering, a benzoxazole ring, or a thiophene ring; each of D⁷¹ to D⁷³ whenthese can be further substituted may have a substituent; L⁷², L⁷³, andE⁷¹ have the same meaning as L²², L²³, and E²¹, respectively; krepresents an integer of 1 to 3; l represents an integer of 0 to 2; k+lis 2 or 3; each of S⁷¹ and S⁷² independently represents a grouprepresented by formula (I); each of n and m represents an integer of 0to 4; n+m is an integer of 1 to 4; and each S⁷¹ or S⁷² may be the sameas or different from every other S⁷¹ or S⁷².
 9. The organicelectroluminescence device as claimed in claim 1, wherein the metalcomplex represented by formula (2) is represented by the followingformula (12):

wherein M¹²¹ represents a metal belonging to Groups 8 to 11 in theperiodic table of elements; each of R¹²³ to R¹²⁵ independentlyrepresents a hydrogen atom or a substituent selected from the groupconsisting of an alkyl group, a fluorine atom, a methoxy group, an arylgroup, a cyano group, and a group of S¹²¹; each of B¹²¹ to B¹²⁴independently represents a nitrogen atom or C—R¹²⁶, wherein the numberof nitrogen atoms of B¹²¹ to B¹²⁴ is 0 or 1, R¹²⁶ represents a hydrogenatom, a group of S¹²², or a substituent selected from the groupconsisting of an alkyl group, a fluorine atom, a methoxy group, an arylgroup, and a cyano group, each R¹²⁶ may be the same as or different fromevery other R¹²⁶; L¹²², L¹²³, and E¹²¹ have the same meaning as L²²,L²³, and E²¹, respectively; k represents an integer of 1 to 3; lrepresents an integer of 0 to 2; k+l is 2 or 3; each of S¹²¹ and S¹²²independently represents a group represented by formula (I); mrepresents an integer of 0 to 4; n represents an integer of 0 to 3; n+mis an integer of 1 to 4; and each S¹²¹ or S¹²² may be the same as ordifferent from every other S¹²¹ or S¹²².
 10. A composition comprising ametal complex of formula (2), formula (14), or a metal complexcomprising a monoanionic bidentate ligand represented by formula (A1-1),having a group represented by the following formula (I):

wherein R₁ represents an alkyl group; each of R₂ and R₃ independentlyrepresents a hydrogen atom or an alkyl group; n^(s) represents aninteger of 0 to 6; and Z represents a saturated 5-, 7-, or 8-memberedring;

formula (2); wherein M²¹ represents a metal belonging to Groups 8 to 11in the periodic table of elements; A²¹ to A²³ each independentlyrepresent a nitrogen atom or a carbon atom; Z²¹ represents a quinolinering, an isoquinoline ring, a benzoxazole ring, a pyridine ring, or apyrazole ring; Z²² represents a benzene ring, a pyrazole ring, apyridine ring, a benzoxazole ring, or a thiophene ring; L²² and L²³ eachrepresent a carbon atom, a nitrogen atom, or an oxygen atom and formtogether with E²¹ a bidentate ligand of a phenylpyridine, apyridylpyridine, a picolinic acid, or an acetylacetone; wherein thebidentate ligand may be further substituted; k represents an integer of1 to 3; l represents an integer of 0 to 2; k+l is 2 or 3; S²¹ and S²²each independently represent the group represented by formula (I); n andm each represent an integer of 0 to 4; n+m is an integer of 1 to 4; andS²¹s or S²²s may be the same as or different from every other S²¹ orS²², respectively; and Z²¹ and Z²² may further comprise an alkyl group,a fluorine atom, and a cyano group;

formula (14); wherein A¹⁴¹ to A¹⁴⁶ each independently represent anitrogen atom or a carbon atom; Z¹⁴¹ and Z¹⁴² each independentlyrepresent an isoquinoline ring, a benzoxazole ring, a pyridine ring, animidazole ring, or a pyrazole ring; Z¹⁴³ and Z¹⁴⁴ each independentlyrepresent an isoquinoline ring, a benzoxazole ring, a benzene ring, apyridine ring, an imidazole ring, or a pyrazole ring; E¹⁴¹ represents adivalent linking group represented by —C(R¹)(R²)—, wherein R¹ and R²represent an alkyl group; S¹⁴¹ to S¹⁴⁴ each independently represent thegroup represented by formula (I); Z¹⁴³ and Z¹⁴⁴ may further comprise analkyl group, a fluorine atom, a methoxy group, an aryl group, or a cyanogroup; n, m, k and l represents an integer of 0 to 2; n+m+k+l is aninteger of 1 to 2; and S¹⁴¹s, S¹⁴²s, S¹⁴³s, S¹⁴⁴s may be the same as ordifferent from every other S¹⁴¹, S¹⁴², S¹⁴³ or S¹⁴⁴, respectively;

formula (A1-1); wherein E_(1f) to E_(1q) each independently represent acarbon atom or a heteroatom; R_(1a) to R_(1i) each independentlyrepresent a hydrogen atom, an alkyl group, a cycloalkyl group, an arylgroup, a cyano group, a fluorine atom, or a group represented by formula(I), wherein at least one of R_(1a) to R_(1i) represents a grouprepresented by formula (I); the framework represented by formula (A1-1)has a structure with 18 π-electrons in total; and the metal complexcomprising the monoanionic bidentate ligand (A1-1) comprises a metalhaving an atomic weight of 40 or more.
 11. A light emitting layercomprising a metal complex of formula (2), formula (14), or a metalcomplex comprising a monoanionic bidentate ligand represented by formula(A1-1), having a group represented by the following formula (I):

wherein R₁ represents an alkyl group; each of R₂ and R₃ independentlyrepresents a hydrogen atom or an alkyl group; n^(s) represents aninteger of 0 to 6; and Z represents a saturated 5-, 7-, or 8-memberedring;

formula (2); wherein M²¹ represents a metal belonging to Groups 8 to 11in the periodic table of elements; A²¹ to A²³ each independentlyrepresent a nitrogen atom or a carbon atom; Z²¹ represents a quinolinering, an isoquinoline ring, a benzoxazole ring, a pyridine ring, or apyrazole ring; Z²² represents a benzene ring, a pyrazole ring, apyridine ring, a benzoxazole ring, or a thiophene ring; L²² and L²³ eachrepresent a carbon atom, a nitrogen atom, or an oxygen atom and formtogether with E²¹ a bidentate ligand of a phenylpyridine, apyridylpyridine, a picolinic acid, or an acetylacetone; wherein thebidentate ligand may be further substituted; k represents an integer of1 to 3; l represents an integer of 0 to 2; k+l is 2 or 3; S²¹ and S²²each independently represent the group represented by formula (I); n andm each represent an integer of 0 to 4; n+m is an integer of 1 to 4; andS²¹s or S²²s may be the same as or different from every other S²¹ orS²², respectively; and Z²¹ and Z²² may further comprise an alkyl group,a fluorine atom, and a cyano group;

formula (14); wherein A¹⁴¹ to A¹⁴⁶ each independently represent anitrogen atom or a carbon atom; Z¹⁴¹ and Z¹⁴² each independentlyrepresent an isoquinoline ring, a benzoxazole ring, a pyridine ring, animidazole ring, or a pyrazole ring; Z¹⁴³ and Z¹⁴⁴ each independentlyrepresent an isoquinoline ring, a benzoxazole ring, a benzene ring, apyridine ring, an imidazole ring, or a pyrazole ring; E¹⁴¹ represents adivalent linking group represented by —C(R¹)(R²)—, wherein R¹ and R²represent an alkyl group; S¹⁴¹ to S¹⁴⁴ each independently represent thegroup represented by formula (I); Z¹⁴³ and Z¹⁴⁴ may further comprise analkyl group, a fluorine atom, a methoxy group, an aryl group, or a cyanogroup; n, m, k and l represents an integer of 0 to 2; n+m+k+l is aninteger of 1 to 2; and S¹⁴¹s, S¹⁴²s, S¹⁴³s, S¹⁴⁴s may be the same as ordifferent from every other S¹⁴¹, S¹⁴², S¹⁴³ or S¹⁴⁴, respectively;

formula (A1-1), wherein E_(1f) to E_(1q) each independently represent acarbon atom or a heteroatom; R_(1a) to R_(1i) each independentlyrepresent a hydrogen atom, an alkyl group, a cycloalkyl group, an arylgroup, a cyano group, a fluorine atom, or a group represented by formula(I), wherein at least one of R_(1a) to R_(1i) represents a grouprepresented by formula (I); the framework represented by formula (A1-1)has a structure with 18 π-electrons in total; and the metal complexcomprising the monoanionic bidentate ligand (A1-1) comprises a metalhaving an atomic weight of 40 or more.
 12. A light emission apparatuscomprising the organic electroluminescence device as claimed in claim 1.13. A display apparatus comprising the organic electroluminescencedevice as claimed in claim
 1. 14. An illumination apparatus comprisingthe organic electroluminescence device as claimed in claim
 1. 15. Theorganic electroluminescence device as claimed in claim 1, wherein atleast one of R_(1a) to R_(1i) is selected from the group consisting of2,6-dimethylphenyl, 2,4,6-trimethylphenyl, 2,6-diisopropylphenyl,2,4,6-triisopropylphenyl, 2,6,-dimethyl-4-phenylphenyl,2,6-dimethyl-4-(2,6-dimethylpyridin-4-yl)phenyl, 2,6-diphenylphenyl,2,6-diphenyl-4-isopropylphenyl, 2,4,6-triphenylphenyl,2,6-diisopropyl-4-(4-isopropylphenyl)phenyl,2,6-diisopropyl-4-(3,5-dimethylphenyl)phenyl,2,6-diisopropyl-4-(pyridine-4-yl)phenyl, and2,6-di-(3,5-dimethylphenyl)phenyl.
 16. The organic electroluminescencedevice as claimed in claim 1, wherein in formula (I), n^(s) representsan integer of 1 to 6.